Medial Lemniscus

Distinct lesions in thin-slice brainstem MRI showed an overlap zone in the medial portion of the medial lemniscus. The finding of putative ipsilateral vestibular projections running adjacent to or within the medial lemniscus was subsequently confirmed by a reanalysis of an anterograde tracer labelling study in the primate after tracer injection in the vestibular nucleus complex. The major conclusions of this study are as follows: (i) there is evidence for an ipsilateral graviceptive pathway running from the vestibular nuclei close to and within the medial lemniscus to the posterolateral thalamus [ ipsilateral vestibulothalamic tract (IVTT)], (ii) this pathway might be the human homologue of the three-neuron sensory vestibulocortical tract described in primates and (iii) unilateral lesions of this pathway cause only vestibulo-perceptive dysfunction in the roll plane in contrast to lesions of the crossed graviceptive pathways (in the medial longitudinal fascicle), which were described earlier and which manifest as a combination of tilt of the subjective visual vertical, ocular torsion and skew deviation..  

5-HTT-IR fibers-of-passage appeared thick, smooth, and unbranched in medial forebrain bundle, medial lemniscus and cortex white matter.  

In addition, the medial lemniscus and several longitudinal bundles in the brainstem and spinal cord are defective.  

The involvement of the mamillothalamic tracts, substantia nigra/medial lemniscus, medial longitudinal fasciculus, the corpus medullare and the cerebellum, with relative sparing of the cortex and subcortical white matter was distinctive and resembled the findings in the first and only known patient with mutation in the NDUFA12L gene..  

In paramedian caudal pontine infarctions, the medial lemniscus is often affected.  

Magnetic resonance images showed that the infarcted areas were located in the ventromedial area of the upper medulla, probably involving the trigeminothalamic tract in the medial lemniscus.  

Several small notches were superimposed on the peaks, and their amplitudes were largest at the contact close to the medial lemniscus.  

Nerve fibers occurred within gracile and cuneate fasciculi, trigeminal spinal tract and nucleus, facial, trigeminal, vestibular and oculomotor nerves, solitary tract, medial longitudinal fasciculus, medial lemniscus, and inferior and superior cerebellar peduncles.  

Cajal clearly described the dorsal column/medial lemniscus pathway, but the presence and course of the spinothalamic tract was unknown at the time..  

The pons was divided into two regions at the most ventral margin of the medial lemniscus at the level of the motor trigeminal nucleus. According to Weigert stained preparations, the first myelinated fibers in each motor root of the trigeminal, abducent, and facial nerves were recognized at 130-140 mm in CRL and the medial lemniscus at 230-235 mm..  

CPSP may be related to hyperexcitation of the spinothalamic pathway by the reticulothalamic system, which in turn is modulated by the medial lemniscus pathway..  

The gustatory tract is generally recognized to be located medially from the medial lemniscus and the reticular formation. Our case suggests that the tract would be located laterally from the medial lemniscus and the reticular formation..  

The CaM III mRNAs were less dominant in the medial lemniscus, the inferior colliculus and the pontine reticular nucleus than those of the other CaM gene-specific transcripts.  

Neurophysiologically, auditory brainstem response and somatosensory evoked potential demonstrated lesions in the cochlear nucleus and medial lemniscus, respectively.  

Thalamic ventrobasal (VB) relay neurons receive information via two major types of glutamatergic synapses, that is, from the medial lemniscus (lemniscal synapses) and primary somatosensory cortex (corticothalamic synapses).  

In cells that were not antidromically activated from the medial lemniscus, short latency orthodromic responses consistent with excitation by recurrent lemniscal collaterals were often observed following lemniscal activation.  

In the mesencephalon, immunoreactive fibers containing thiamine were only found at rostral level close to the medial lemniscus (at the mesencephalic-diencephalic junction).  

Six areas of the brain were analyzed: the medial cortex, hippocampus, lateral cortex, thalamus, medial lemniscus, and medial longitudinal fasciculus.  

Quantitative analysis was performed using the regions of interest (ROI) method settled on the central part of all identifiable WM fibres, including the corticospinal tract (CST) in the brainstem, middle cerebellar peduncle (MCP), medial lemniscus (ML), anterior/posterior limb of internal capsule (ICAL/ICPL), arcuate fasciculus (AF), posterior thalamic radiation (PTR), genu of corpus callosum (GCC), splenium of corpus callosum (SCC), corona radiata (CR), cingulum (CG), and superior longitudinal fasciculus (SLF).  

In addition, there is often selective, symmetric involvement of the corticospinal tract, the medial lemniscus, and the tractus solitarius.  

HFOs recorded at brainstem might be produced by volume conduction from oscillations of the medial lemniscus.  

Using single-label immunocytochemistry employing the antibodies RM014, APP, or a combined labeling strategy targeting APP/RMO14 in aggregate, the immunoreactive (IR) profiles were counted in the corticospinal tract (CSpT) and medial lemniscus (ML).  

The dorsal column nuclei (DCN; gracile and cuneate nuclei) give rise to the medial lemniscus, the fibre system that provides an organised somatosensory input to the thalamus. Unlike the spinothalamic and trigeminothalamic tracts that project, also to the ipsilateral thalamus, the medial lemniscus system is believed to be entirely crossed.  

Axial, sagittal, and coronal images demonstrated major white-matter fibers within the brain stem, including cortico-spinal tracts, transverse pontine fibers, and medial lemniscus.  

MR imaging revealed a new cerebral microbleed in the medial lemniscus of the right side in the mid-pontine region.  

On MRI, the lesion was thought to involve the spinothalamic tract, medial lemniscus and inferior olivary nucleus.  

Using glutamate receptor antagonists, we isolated inhibitory postsynaptic potentials and currents (IPSPs and IPSCs) evoked by high-threshold stimulation of medial lemniscus.  

Fewer fibers were associated with the superior cerebellar peduncle, medial lemniscus, and nigrostriatal pathway.  

All appropriately studied patients had hypoplasia of the pons and cerebellar peduncles with both anterior and posterior midline clefts of the pons and medulla and electrophysiologic evidence of ipsilateral corticospinal and dorsal column-medial lemniscus tract innervation.  

A significant decrease in amplitude of the cortical response may indicate either a compromise of neural conduction in the spinothalamic tracts of the dorsal column medial lemniscus system or the effect of anesthesia, an innocuous event.  

Unexpectedly, we also noted the transient expression of MIDC-8 antigen on cells within the medial ganglionic eminence and by neuroepithelial cells lining the lateral ventricles and in the medial lemniscus between E15 and E19.  

Smaller numbers of projection neurons were located in the PTL, zone A and outside the zone B among fibers of the medial lemniscus.  

Cortical responses to stimulation of the medial lemniscus (ML) were virtually absent during silent periods. We conclude that the preserved ability of the somatosensory system to transmit the peripheral stimuli to the cerebral cortex during all the phases of sleep slow oscillation is based on the functional properties of the medial lemniscus and on the intrinsic properties of the thalamocortical cells.  

The VFOs from STN probably represent volume conduction, possibly from the medial lemniscus.  

The similarity and differences in the gracile response features in comparison with the thalamic recordings suggest that somatovisceral interactions take place at multiple levels in the dorsal column-medial lemniscus system..  

In this system, axons from the second-order neurons in the dorsal column nuclei form the internal arcuate fibers, cross the ventral midline (floor plate) within the medulla oblongata, and then project to the thalamus as the medial lemniscus.  

Some fibers of the lateral leminiscus appear to reach the thalamus in conjunction with fibers of the medial lemniscus..  

Traditionally, the dorsal column-medial lemniscus system has been viewed as a pathway not involved in pain perception.  

Two types of neurons were identified: low firing rate (LF) neurons, which could be activated antidromically by medial lemniscus stimulation; and high firing rate (HF) neurons.  

RECENT FINDINGS: Abnormalities in the corpus callosum, corticospinal tract, medial lemniscus and cerebellar peduncles can be seen in holoprosencephaly.  

In contrast to the function of the visual or auditory pathways which are electrophysiologically accessible by visual or auditory evoked potentials, the somatosensory pathway cannot be investigated as a whole by conventional somatosensory evoked potentials (SEP), because these only reflect function of large fibers, dorsal columns, medial lemniscus and their thalamo-cortical projections mediating sensations like touch and vibration.  

These results suggest a spatial segregation of the neural populations that process signals conveyed by dorsal column-medial lemniscus (nonpainful signals) and neospinothalamic (painful signals) pathways.  

Electrical stimulation of the medial lemniscus or TRN resulted in the generation of complex synaptic potentials containing disynaptic inhibitory post-synaptic potentials (IPSPs) in VB thalamocortical neurones.  

Standard clinical neurophysiological assessment of somatosensory pathways by sensory evoked potentials (SEPs) is limited to the tactile and proprioceptive systems consisting of large fibers in the peripheral nerve, the dorsal columns of the spinal cord and the medial lemniscus in the brainstem.  

Abnormal high signal on T2-W images was seen in the dentate nucleus, substantia nigra and the pontine medial lemniscus in 79, 43 and 64%, respectively.  

The use of 100 microm serial sections through the SCA2 patient's central somatosensory components showed that obvious neuronal loss occurred in nearly all of the relay stations of this system (Clarke's column; cuneate, external cuneate and gracile nuclei; spinal, principal and mesencephalic trigeminal nuclei; ventral posterior lateral and ventral posterior medial nuclei of the thalamus), whereas the majority of interconnecting fibre tracts (dorsal spinocerebellar tract; cuneate and gracile fascicles; medial lemniscus; spinal trigeminal tract, trigeminal nerve and mesencephalic trigeminal tract) displayed signs of atrophy accompanied by demyelinization.  

Meanwhile there are some specific lesions of the brain stem's tracts (the posterior limb of the internal capsule, the splenium of the corpus callosum, the medial lemniscus and the mesencephalic trigeminal tracts).  

Using paraesthesia as the behavioural-physiological response threshold, we measured chronaxie times for microstimuli applied to both somatosensory thalamic nuclei (cellular region) and its axonal afferents, the medial lemniscus. White matter chronaxie times were relatively unimodal, whereas two different clusters of chronaxie times were identified in grey matter: one corresponding to that of the medial lemniscus and the other about five times longer and compatible with that obtained from cell somata.  

Corticospinal, corticobulbar, and corticothalamic tracts, the corpus callosum, the limbic system, several cortical association bundles, the cerebellar peduncles, and the medial lemniscus were all investigated.  

The overlapping area associated with loss of N20 coincided with the location of the medial lemniscus. The loss of N18 in SSEPs had a statistically significant correlation with bad outcome, which suggests the superiority of SSEPs for predicting the outcome of stroke and indicates the involvement of some system excluding the medial lemniscus in the generation of N18..  

Similarly, there was IgG deposition within the posterior-column/medial lemniscal sensory system, including the arcuate fibers of the cranial-cervical junction, the nucleus cuneatus, and throughout the course of the medial lemniscus in the medulla, pons, and midbrain.  

Electrical stimulation of the contralateral medial lemniscus and of the skin at sites evoking responses with minimal threshold induced recurrent activation of CL cells at a latency of 1-3.5 ms.  

Recent discoveries of visceral nociceptive inputs sharing the classical tactile pathway in the dorsal-column medial lemniscus system have opened a new venue for the investigation of somatovisceral interactions.  

By 12 h postinjury, caspase-3-mediated APP proteolysis (CMAP) was demonstrated within the medial lemniscus (ML) and medial longitudinal fasciculus (MLF) in axons undergoing TAI, identified by their concomitant APP accumulation.  

Sensory inputs from the whiskers reach the primary somatosensory thalamus through the medial lemniscus tract.  

In the primary somatosensory thalamus (ventrobasal thalamus), sensory inputs deliver tactile information through the medial lemniscus tract.  

We believe that if medullary cervical junctional involvement extends slightly higher (in rare circumstances), with involvement of one of the branches of the vertebral or lower basilar artery, medial medullary syndrome will occur, sparing medial lemniscus and emerging hypoglossal nerve fibres.  

It was possible to identify the corticospinal tract (CST), medial lemniscus, and the superior, medial, and inferior cerebellar peduncles.  

vestibular and cochlear nuclei, cells and fibers at the floor of the fourth ventricle with morphologic features of tanycytes, parabrachial nuclei (PBN), medial lemniscus, lateral lemniscus, inferior cerebellar peduncle and cerebellar white matter, central tegmental tract, and the capsule of the red nucleus.  

substantia nigra, red nucleus, inferior colliculus, medial lemniscus, and pontine nuclei expressed D2, but not D1, mRNA.  

The central gustatory pathway ascends from the solitary tract nucleus in the medulla up to the upper pons in the ipsilateral central tegmental tract, rather than in the medial lemniscus as proposed in the past.  

BACKGROUND: Restricted sensory deficits along the somatotopic topography of the medial lemniscus rarely develop in medial medullary infarction. CONCLUSIONS: The patient showed lemniscal sensory deficits below the right L5 dermatome that were caused by the partial involvement of the medial lemniscus.  

The APT left the pyramidal tract within the crus cerebri and passed in the medial lemniscus of the pons through the upper medulla oblongata.  

Low-frequency cells (74%) were silent or displayed a low firing rate (1.9+/-0.48 spikes/s), and were identified as thalamic-projecting neurons because they were activated antidromically by medial lemniscus stimulation. None of them was antidromically activated by medial lemniscus stimulation.  

Our case suggests that the central gustatory pathway projecting from the nucleus of the solitary tract to the parabrachial nucleus, presumed to be pontine taste area, ascends ipsilaterally and is located laterally from the medial lemniscus..  

We have evaluated the effects of a direct infusion of histamine, as mediator of inflammatory response, in substantia nigra, striatum, medial septum, and medial lemniscus. Moreover, intraseptal injection of 100 nmol of histamine failed to alter the pattern of choline acetyltransferase mRNA-expressing cells, and intraparenchymal injection of histamine in medial lemniscus failed to alter the pattern of serotonin-immunolabeled cells.  

Responses of these neurons to electrical stimulation of trigeminothalamic tract (TTT) fibers in the trigeminal medial lemniscus were also inhibited following PAG/NRD stimulation.  

Injections of either diI or HRP into the lateral funicular complex label fibers of the medial lemniscus which crosses the midline in the caudal medulla to ascend along the ventral margin of the contralateral rhombencephalon. Within the medulla, fibers leave the medial lemniscus to terminate in the inferior olive and in the ventrolateral medullary reticular formation. Upon reaching the midbrain, the medial lemniscus turns dorsally to terminate heavily in a lateral division of the torus semicircularis, in the ventral optic tectum, and in the lateral subnucleus of the nuc.  

There was evidence for loss of axons of atrophic CN cells in the medial lemniscus and in the thalamus, with accompanying severe disorganization of the parts of the ventral posterior nuclei representing the normally innervated face and the deafferented upper limb.  

CONCLUSION: The pyramidal tract and the dorsal column-medial lemniscus pathway did not cross in the medulla in this patient. In view of the presence of the abnormal shape in the medulla and congenital scoliosis, a congenital factor might be responsible for the uncrossed pyramidal tract and dorsal column-medial lemniscus in this patient..  

Intracellular recordings were obtained from cuneate neurons of chloralose-anesthetized, paralysed cats to study the synaptic responses induced by electrical stimulation of the contralateral medial lemniscus. From a total of 178 cells sampled, 109 were antidromically fired from the medial lemniscus, 82 of which showed spontaneous bursting activity. medial lemniscus stimulation induced recurrent excitation and inhibition on cuneolemniscal and non-lemniscal cells. Some other non-lemniscal cells that did not respond to medial lemniscus stimulation in control conditions were transcortically affected by stimulating the medial lemniscus after inducing paroxysmal activity in the sensorimotor cortex.  

Specifically, the corpus callosum, internal and external capsules, medial lemniscus, tegmentum of the mesencephalon and metencephalon, and cerebellar peduncles showed significantly higher 14C-CB 153 than the other structures.  

Pontine PSS involved the medial lemniscus together with the ventral trigeminothalamic tract, sparing the anterior and lateral spinothalamic tracts.  

The N13b (dorsal column near the foramen magnum or cuneate nucleus) was observed in all children and in 16 adults, P14 (medial lemniscus) in 52 children and 17 adults.  

Electrolytic lesion of the pyramidal tract abolished the cortically induced effects on the contralateral cuneate nucleus, as well as on the ipsilateral medial lemniscus.  

In the brainstem the ventral ramus of TSM was situated ventral to the medial lemniscus at the base of the brain, entered the spinal cord in the inner margin of the lateral funiculus, predominantly ipsilaterally, and terminated bilaterally but predominantly contralaterally in the medial part of the base of the dorsal horn of the upper six or seven cervical segments.  

Moreover, the staining in VPL of mice was markedly reduced after transection of axons that travel to the thalamus in the medial lemniscus, suggesting that much of it was contained in these afferent fibers.  

The gustatory pathway is generally said to exist around the medial lemniscus and the reticular formation.  

At P12, maximal levels were measured in the medial lemniscus and cerebral peduncle.  

However, the nature, the mode of onset, and aggravating factors are different between the 2 groups, which probably is related to a selective involvement of the spinothalamic tract by the former and the medial lemniscus by the latter.  

Brain MRI showed diffuse, symmetrical white matter hyperintensities in the cerebellum, posterior cerebrum, posterior limbs of the internal capsule, splenium of the corpus callosum, medial lemniscus, and lateral brainstem.  

Of these, many were also excited by electrical stimulation of trigeminothalamic tract (TTT) fibers in the trigeminal medial lemniscus.  

Displacement of major tracts, such as the medial lemniscus or corticospinal tract, as well as fiber directionality, was also easily recognized in cases of mass lesions.  

Neurons belonging to the dorsal column nuclei (main cuneate nucleus and gracile nucleus), or to the ventral posterolateral nucleus, were sampled for their response to stimulation of the peripheral cutaneous fields, as well as the antidromic response to stimulation of the contralateral medial lemniscus and ipsilateral somatosensory cortex, respectively.  

We examined the extent and distribution of disturbances in deep sensation and compared the findings with the lesion location in the medial lemniscus detected by MRI in 3 patients with medial medullary infarction. Type I was ventral to the middle medial lesion of the medial lemniscus, and type II was ventral to the dorsal medial lesion. It is concluded that hemiparesis appeared with lesions located in the pyramidal tract of the medulla, hemiparesis and disturbance of deep sensation in the upper and lower extremities, predominantly in the lower extremities with the lesion of the pyramidal tract to the middle of medial lemniscus in the medulla, hemiparesis and disturbance of the upper and lower extremities deep sensation with lesions of the pyramidal tract to the whole of the medial lemniscus in the medulla. Evaluating deep sensation of the upper and lower extremities is useful for speculation of the lesion location in the medial lemniscus in medial medullary infarction..  

However, there was scant morphine effect on responses to stimulation of trigeminothalamic tract (TTT) fibers in the trigeminal medial lemniscus.  

As the lesion on the left side was larger than that on the right, the foot area in the left medial lemniscus was involved, causing paresthesia in the right toes.  

These fibers coursed medially through the cerebral peduncle and substantia nigra to reach some restricted areas of the mesencephalic reticular formation between the medial lemniscus and the substantia nigra..  

The vocalization region most likely consists of axons arising in the midbrain periaqueductal gray and coursing through the adjacent tegmentum; low-threshold sites are close to the medial lemniscus.  

Results of coupling peripheral stimuli and stimuli to medial lemniscus (LM) are explained by a shorter LM latency and/or a longer peripheral latency.  

Associated partial sensory disturbance of the face or limb with lack of evidence of medial lemniscus decussation at the upper brainstem suggests that the medial lemniscus may not directly convey taste sensation..  

Patient 1 had sensory symptoms restricted to the contralateral foot secondary to an infarct selectively involving the ventral portion of the medial lemniscus that probably corresponds to leg-representing area. Our MRI-clinical correlation study is consistent with the previously reported sensory topography of the medial lemniscus and the ascending trigeminal tract: the leg-representing area is located ventrally in the medial lemniscus whereas the perioral-representing area is situated most medially in the ascending trigeminal tract..  

Stimulation of the contralateral medial lemniscus permitted us to separate projection cells from presumed interneurons.  

In the median raphe nucleus (B8) and the B9 cell group in the medial lemniscus, 8-OH-DPAT induced a marked decrease in labeling 30 min after injection.  

Single shocks applied to the ventral quadrant of the cord or in the medial lemniscus (LM) in the medulla oblongata induced monosynaptic excitatory post-synaptic potentials (EPSPs) in most rubrospinal cells.  

Ascending projections from Cu and CuE form the contralateral medial lemniscus, which has extensive projections to the midbrain and to the thalamus.  

Of the 4 patients, 1 patient had pontine infarction, including medial lemniscus, and severe sensory deficit and 3 had small localized lesions in the lateral part of the thalamus and neither sensory impairment nor abnormal N20 waves on somatosensory evoked potential recordings.  

SEP with right posterior tibial nerve stimulation showed a delayed central conduction time, suggesting that the lesion involved left medial lemniscus. These findings support the idea that the supranuclear facial nerve fiber leaves the pyramidal tract at the upper to middle pons and descends in the area of the pontine tegmentum around the medial lemniscus..  

As judged from relative signal intensities, myelin was present at the post-conceptional age of 30-34 weeks in the following structures: tegmentum pontis (in particular medial lemniscus), superior and inferior colliculi, decussation of the superior cerebellar peduncles, crura cerebri, ventrolateral thalamus, lateral globus pallidus, dorsolateral putamen, dentate nucleus, middle and superior cerebellar peduncles, vermis cerebelli, cortex bordering the central sulcus and hippocampus.  

On this basis, it is possible to identify the nuclei of the human motor thalamus that transfer information from the substantia nigra, globus pallidus, cerebellum, and proprioceptive components of the medial lemniscus to prefrontal, premotor, motor, and somatosensory areas of the cerebral cortex.  

Low-frequency (LF) neurons (77%) had very low spontaneous activity, and most could be antidromically activated from the medial lemniscus.  

5-HT SLN cells are located within or dorsal to the medial lemniscus (ML); those of the PMRF are widely distributed throughout the PMRF.  

On this basis, it is possible to identify the nuclei of the human motor thalamus that transfer information from the substantia nigra, globus pallidus, cerebellum, and proprioceptive components of the medial lemniscus to prefrontal, premotor, motor, and somatosensory areas of the cerebral cortex.  

These clinical observations suggest that P30 potential, as P14 of median nerve somatosensory evoked potentials, is generated in the lower brain stem probably before the decussation of the sensory fibers; nucleus gracilis and medial lemniscus fibers in the lower brain stem are probably the anatomical structures generating P30 potential.  

P13/14 on the affected side normally preserved at the first examination progressively declined and finally disappeared after 4 months, which suggested that the major part of P13/14 is generated within caudalmost medial lemniscus, as well as the occurrence of retrograde degeneration of lemniscal fibers..  

We suggest that in patients showing SEP abnormalities, the dysfunction of the central somatosensory conduction is located above the medial lemniscus and is limited to common peroneal nerve somatosensory pathways. Therefore, it is likely that in the seven patients showing SEP abnormalities, the loss of the knee mechanoreceptors was followed by remodelling of the CNS above the medial lemniscus.  

We presume that activation of VPL neurons by noxious visceral stimulation contributes to visceral pain sensation and thus that pelvic visceral pain depends largely on activity in the DC-medial lemniscus system..  

In general, the touch and deep sensation are carried through the medial lemniscus located in the medial medulla, therefore central pain is not considered to be induced by the medial medullary lesion.  

In patients with normal N11 and N13, prolongation of P14, originating from the medial lemniscus, indicated a compressive lesion located above the level of entry to the spinal cord of the nerve stimulated.  

Field potential responses of the somatosensory cortex to a periodic medial lemniscus (ML) fiber stimulation were investigated in anesthetized rats.  

Under this condition, application of baclofen decreased the amplitude of the medial lemniscus- and optic tract-evoked excitatory postsynaptic potentials in the two thalamic nuclei investigated.  

STT/SHT neurons were antidromically activated with currents < or = 30 microA from the medial lemniscus (ML), anterior pretectal nucleus (APt), posterior nuclear group and medial geniculate nucleus (Po/MG), and zona incerta in the thalamus and from the optic tract (OT), supraoptic decussation, or lateral area of the hypothalamus.  

(3) The ventral retrorubral area close to the medial lemniscus projects to all rostrocaudal levels of the caudate nucleus.  

Paresthesiae-producing deep brain stimulation (stimulation of ventrocaudal nucleus-VC, medial lemniscus-ML or internal capsule-IC) is one of the few procedures to treat the steady element of neural injury pain (NIP) currently available.  

The results suggest that P14 reflects the spike volley in caudal medial lemniscus, and that the N18 neural generators are located in the medulla, probably in the dorsal column nuclei and/or the accessory inferior olives..  

Descending fibers from the NOT consisted of two major pathways: (1) fibers descended medially from the injection site through the reticularis pontis oralis to reach the lateral part of the ipsilateral nucleus reticularis tegmenti pontis; (2) fibers projecting into the dorsal cap of inferior olive, by far the greatest number of labeled fibers, descended ventrally along the lateral border of the reticularis pontis oralis and reached the medial lemniscus where they descended further and branched into the dorsolateral pontine nucleus, the lateral part of the nucleus reticularis tegmenti pontis, the peduncular pontine nucleus, the lateral pontine nucleus, the nucleus prepositus hypoglossi, the medial vestibular nucleus and finally the dorsal cap of the inferior olive.  

The present study focused on the efferent connections of the DCN, in particular the targets of the medial lemniscus. The medial lemniscus could be traced throughout the brainstem and into the diencephalon. Along its course, the medial lemniscus gives off collaterals to various parts of the reticular formation, to the octavolateral area, and to the granular layer of the cerebellum. At mesencephalic levels, the medial lemniscus innervates the lateral part of the torus semicircularis as well as various tegmental nuclei. Beyond the midbrain, both dorsal and ventral thalamic areas are innervated by the medial lemniscus.  

Fibres en passant were detected in the medial lemniscus, from the level of the injection site to rostral medullary levels.  

These data indicate that the de novo synthesized SP in the lesioned primary afferent neurons may be involved in an augmentation of excitability in the dorsal column-medial lemniscus sensory pathway.  

Most incertopontine axons descend to the basilar pons in association with fibers of the medial lemniscus or crus cerebri and reach ipsilateral ventral and medial pontine gray regions. The anterior pretectal axons also descend with the medial lemniscus and crus cerebri to enter exclusively the ipsilateral basilar pons where they terminate most densely in ventral and medial regions.  

At the brainstem level, the ascending spinorubral fibres follow the medial lemniscus (LM).  

An estimate of the conduction velocity of the medial lemniscus pointed towards a subthalamic origin.  

Evoked responses were recorded in the thalamic ventralis posterior nucleus after stimulation of the medial lemniscus or the cuneate bundle in the spinal cord.  

Diffusion-filled lemniscal axons were labeled by WGA-HRP injections aimed at the medial lemniscus. There was no conspicuous alteration of axonal stems in the medial lemniscus.  

Lesions were localized in the medial lemniscus of the middle and lower pons, with a sparing of the spinothalamic tracts.  

After a survival period of 72 h, the greatest number of labelled cells was visualized in the substantia nigra, with lower numbers in adjacent structures (ventral tegmental area, zona incerta and medial lemniscus).  

The cells were tested for antidromic activation from the contralateral medial lemniscus and the contralateral tectum. Sixty (83%) projected through the medial lemniscus, and of these 36 (50% of the total) also projected to the tectum, whereas 24 (33%) projected through the medial lemniscus only; 12 (17%) projected only to the tectum. Twenty-nine units (40%) were excited by moving hairs of the coat but not by pinch of the skin, and 9 (31%) of these projected to the tectum, 11 (38%) through the medial lemniscus and 9 (31%) to both targets. Forty units (56%) were excited by hair movement and noxious pinch, and 3 (7%) of these projected to the tectum, 10 (25%) through the medial lemniscus and 27 (68%) to both targets. Three units (4%) had no discernible receptive fields and they all projected through the medial lemniscus, but not to the tectum. Units projecting either through the medial lemniscus only, or through the medial lemniscus and also into the tectum, had receptive fields more widely distributed: these included small fields on the fore- and hind feet, on the limbs and also, a minority, on the trunk. Units with glove- or stocking-like receptive fields projected through the medial lemniscus. The results show that while most LCN cells project through the medial lemniscus, those excited by hair movement alone preferentially project either to the tectum or through the medial lemniscus, but not by both routes.  

MRI showed a small lacune in the left paramedian pontine tegmentum corresponding to the location of the medial lemniscus.  

It appears that severe central nervous system lesions, with total destruction of ascending sensory systems, do not lead to a central pain syndrome; and that setting of mild, moderate, or severe disruption of the anterolateral ascending system with partial or complete preservation of the dorsal column/medial lemniscus functions is most frequently associated with central pain syndrome. Furthermore, even during remission, dysesthesias and pain could be triggered by additional afferent input to the large fiber/dorsal column/medial lemniscus system and, once established, they may not be abolished by additional deafferentation..  

The internal capsule, the medial lemniscus, the crus cerebri and the thalamic radiations were used by both populations of transplant derived macroglial cells for their migrations through the host parenchyma.  

Following biocytin injections into NOT, labeled fibers were observed in each of the following efferent pathways: (1) those that project to the contralateral NOT via the posterior commissure; (2) those that course through the nucleus reticularis pontis oralis to terminate in the nucleus reticularis tegmenti pontis; and (3) those that descend via the medial lemniscus to the level of the medulla to terminate in the dorsolateral pontine nucleus, nucleus prepositus hypoglossi, medial vestibular nucleus and the inferior olive.  

In addition, it is suggested that the pathways of late blink reflex (R2) pass through the medial lemniscus in the ventromedial medulla instead of the spinal trigeminal tract in the dorsolateral medulla. Further, the observation of the much longer lantencies (about 29 ms) of the normal R2 raises the possibility that the impulses may travel along the longer pathways through the opposite medial lemniscus and up to the thalamus or cortex where they project to bilateral motoneurons of the orbicularis oculi muscles.  

In Xenopus laevis fluorescent dextran amines were applied to study the development of the dorsal column-medial lemniscal projection: rhodamine dextran amine was applied at the mesodiencephalic border to retrogradely label the cells of origin of the medial lemniscus in the dorsal column nucleus (DCN); fluorescein dextran amine to the spinal cord to anterogradely label the primary afferent projections to the DCN.  

Rats with additional damage to adjacent structures, such as the medial lemniscus and olivary complex, were much more severely impaired on the reaching tasks, and displayed similar impairments as judged by qualitative and kinematic measures.  

Both approaches are indicated for focal intra-axial lesions located unilaterally and dorsal to the medial lemniscus in the lower midbrain to the pons.  

Animals with either a light-conditioned stimulus or with electrical stimulation of the ventral pontine nucleus as a conditioned stimulus rapidly learned to avoid an aversive event, while those with no conditioned stimulus, with electrical stimulation of the lateral pontine nucleus or the medial lemniscus did not learn to avoid.  

Considering the clinical symptoms and radiological findings of these cases, it appears that a lesion which causes such rare neurological symptoms may involve the medial lemniscus, spinothalamic tract, lateral lemniscus, spinocerebellar fiber, and central tegmental tract at the tegmentum of the middle pons on the side contralateral to the cerebellar signs and pseudoathetosis..  

The activity of neurons of the sensorimotor cortex during the paired combination of stimulations of brain structures (the medial lemniscus, the reticular nucleus of the midbrain tegmentum, and the pyramidal tract), with an interstimulus interval of 1.2 sec, was investigated in awake nonimmobilized rabbits.  

Injection of biocytin in the LPT area containing most of the HRP-labeled neurons caused anterograde labeling of fibers that crossed the midline and ascended just dorsal to the contralateral medial lemniscus.  

At midgestation, GAP-43 immunostaining was moderately intense across nuclei and fiber tracts, except for the corticospinal tract, where levels were higher, and cranial nerve nucleus VII, superior olive, inferior colliculus, inferior olivary hilum, inferior cerebellar peduncle, medial lemniscus, and medial longitudinal fasciculus, where staining was nearly absent.  

They were bilateral and involved the area of the nucleus reticularis pontis caudalis, left medial lemniscus and roots of several cranial nerves, especially the VIth.  

Brain CT and MRI showed a pontine hematoma involving the right medial lemniscus, the right spinothalamic tract and the right medial longitudinal fasciculus.  

Though cranial CT scan failed to find out new abnormality, T2-weighted cranial MRI disclosed high intensity spot over left pontine base located between medial lemniscus and pyramidal tract, which was supposed to coincide to fascicle of left abducens nerve Three months later, he recovered in the same manner as 2 years before.  

Injection of glutamate and lidocaine into NRM demonstrated that these effects were due to activation of NRM neurons and not to current spread to medial lemniscus (ML).  

We examined 2 cases of cheiro-oral-pedal syndrome; the lesion responsible was confirmed by magnetic resonance imaging to be in the medial lemniscus and in the ventral ascending tract of the trigeminal nerve..  

The field potentials and the unit activities were evoked in the VB by the electrical stimulation of the contralateral (cSCx) and ipsilateral somatosensory cortex (SCx), the thalamic radiation (TR), and the medial lemniscus (ML).  

In the brain stem the fibers join the medial lemniscus.  

Type I-ir glia were observed in some fiber systems, e.g., corpus callosum, medial lemniscus, cerebral peduncles, spinal trigeminal tract, and funiculi of the spinal cord.  

After the P9 and P11 far-fields, the nasopharyngeal SEPs disclosed a negative-going component which was interpreted as the near-field equivalent of the P14 scalp far-field generated in the caudal part of the medial lemniscus.  

The receptive fields of the recorded units were analyzed and the units tested for inputs from the medial lemniscus (ML) and spinothalamic tract (STT) by electrical stimulation of the dorsal columns (DC) and ventrolateral funiculus (VLF) at the C2-3 spinal level.  

Vibration, joint position and movement as well as discriminatory touch each seem to be served by separate fibres of the posterior columns and medial lemniscus.  

There were 71 neurons antidromically activated from the contralateral thalamic ventro-basal complex (VB) or medial lemniscus.  

The medial lemniscus conducts the discriminatory tactile and the deep sensory impulses from the extremities.  

This pattern of immunostaining persisted up to the oldest age studied (day 28 postnatal), except in the lateral septal and parabrachial nuclei, along the dorsal border of the medial lemniscus, and in the inferior olive, where many of the previously immunopositive cells could no longer be detected.  

Widespread N18 potential to median nerve stimulation was preserved in a patient who had profound unilateral disturbance of deep sensation and a lesion of the pontine medial lemniscus confirmed by MRI.  

Four patients had abnormal SEPs seen in patients with the lesions in the central nervous system (dorsal column, medial lemniscus).  

When retrograde tracing from the colliculus was combined with immunocytochemistry for serotonin, cells containing both labels were found in the lateral portions of the nucleus raphe dorsalis and also in periaqueductal gray, the median and pontine raphe nuclei, and in the region of the medial lemniscus.  

This evoked responses remain after unilateral section of the medial lemniscus.  

These THP-reactive sites comprise the substantia nigra, reticular formation, medial lemniscus, zona incerta, medial forebrain bundle, nucleus accumbens, olfactory tubercle, lateral septal nucleus, preoptic area, stria terminalis, and rostral hippocampus.  

The result of somatosensory evoked potential testing was compatible with disturbance of the medullary medial lemniscus.  

N1 can be attributed to the cuneate nucleus and medial lemniscus, N2 to the primary somatosensory cortex and N3 to the frontal cortex..  

The electrodes were implanted in the primary somatosensory cortex, cortical somatosensory radiation, medial lemniscus and midbrain reticular formation. Alterations in the excitability of the primary sensory pathway were assessed by the changes of the input to and output from these brain areas: the response in the medial lemniscus to the stimulation of the skin represented the input to the thalamic relay nucleus and the response recorded in the cortical sensory radiation represented the output from the thalamic relay nucleus. The response in the cortical radiation to stimulation of the medial lemniscus was suppressed by 20% of the control and the postsynaptic component of the cortical response to the stimulation of the medial lemniscus was suppressed by more than 50% of the control.  

CBF was measured in the frontal cortex, somatosensory cortex, thalamus (nucleus ventralis posterior lateralis-VPL), medial lemniscus (ML), lateral lemniscus (LL) and caudate nucleus (CN).  

Electrical stimulation of the brain of the domestic cat elicited vocalizations from a site in the ventrolateral pons in the region of the medial lemniscus.  

In the thalamus a negative potential with almost the same latency as the scalp N18 was restricted to the Vim nucleus, but there was a large positive potential in the VC nucleus and medial lemniscus.  

Recordings from both generally anesthetized as well as locally anesthetized, but awake preparations, indicated that pyramidal tract and cerebrocerebellar projection neurons never fired action potentials spontaneously or were orthodromically activated following stimulation of the medial lemniscus. Stimulation of the medial lemniscus did synaptically activate neurons in the cortex, but these were always located superficial to the antidromically activated projection neurons.  

The results show that the majority of ascending projections decussate via internal arcuate fibers to form a contralateral medial lemniscus which ascends in a ventral position. The distribution of the cells of origin of the medial lemniscus (ML) within the DCN/CuE complex was found to be largely coextensive with the areas of termination of primary spinal (Wild: J.  

Significant change was not observed in the medullary medial lemniscus in any case.  

The BAEP and SEP abnormalities indicated a conduction failure of the acoustic lateral lemniscus pathway and the medial lemniscus pathway in the brainstem of the patients with NB.  

Structures sensitive to the inhibitory action of the aldehyde adduct included the substantia nigra, reticular formation, medial lemniscus, preoptic area, nucleus accumbens, olfactory tubercle, cingulate gyrus and rostral hippocampus.  

High resolution magnetic resonance imaging revealed a small lesion at the paramedian pontine tegmentum in both cases and suggested involvement of the medial portion of the medial lemniscus..  

Structures sensitive to THP included the substantia nigra, reticular formation, medial lemniscus, zona incerta and medial forebrain bundle.  

In the post mortem examination, the lesion extended unilaterally into the pontine tegmentum, partially involving the left medial lemniscus.  

The GAL-IR terminal fields continue caudally in the mesodiencephalic junction and merge with other GAL-IR fibers in the dorsal aspects of the substantia nigra and around the dorsolateral tip of the medial lemniscus.  

Injections of propidium iodide (PI) into the lateral cerebral ventricle of the rat resulted in a bilateral labeling in the septohippocampal nuclei, substantia nigra (SN), ventral tegmental area (VTA), retrorubral nuclei (rr), dorsal and median raphe nuclei, regions within and dorsal to the medial lemniscus of the caudal midbrain, and Purkinje cells in the cerebellum.  

Interpeak latency of I-V in ABR represents the brainstem dysfunction in auditory pathway, and interpeak latency of N13-N19 in SSEP was recognized as central conduction time from medial lemniscus to primary sensory area of cortex.  

Furthermore, the involvement of the so-called aberrant pyramidal tract in the pontine medial lemniscus indicated that retrograde degeneration had occurred there as well..  

Magnetic resonance images showed a small lacune in the right paramedian pons corresponding to the location of the medial lemniscus..  

In awake mobile rabbits, with electrodes implanted in the medial lemniscus, midbrain tegmental reticular nucleus, and pyramidal tract, combined stimulation of two brain of two brain structures resulted in elaboration of conditional connections in sensorimotor cortex neuronal populations.  

(ii) III-a, III-b, and III-c originate between the decussation of the medial lemniscus and the thalamus. (iii) PIII probably originates from multiple structures rostral and caudal to the decussation of the medial lemniscus.  

CT, MRI and neurological findings showed that the syndrome was due to a lesion in the medial lemniscus and ventral secondary ascending tract of the trigeminal nerve on both sides.  

Using this model, we assessed brain stem function by brain stem auditory evoked potential (BAEP), surface- and depth-recorded (in medial lemniscus) short latency somatosensory evoked potential (SSEP), blink reflex (BR) and electroencephalography (EEG), and investigated the correlation between the electrophysiological abnormalities and the lesion in the brain stem.  

SBP-immunoreactive neuronal perikarya were present in the nuclei raphe dorsalis, raphe centralis superior, raphe medianus, raphe magnus, raphe obscurus, raphe pallidus, dorsal to the medial lemniscus in the region of the B9 cell group, near the interpeduncular nucleus, in the area postrema, the pars compacta of the substantia nigra, the dorsomedial nucleus of the hypothalamus, and the arcuate nucleus.  

Axons were characterized in terms of their latencies of response to stimulation of the medial lemniscus in the medulla, their receptive fields, and the temporal patterns of their discharge in response to stimulation of the receptive field with natural, hand-held stimuli.  

On awake nonimmobilized rabbits, evoked activity was studied of the sensorimotor cortex neurons in response to stimulation of the pyramidal tract, medial lemniscus and reticular nucleus of the midbrain tegmentum by stimuli of different frequencies, and driving reaction of cortical neurons to stimulation of these brain structures by series of stimuli of increasing frequency.  

After injection of the radioactive tracer ([ 3H] wheat germ agglutinin) into the lateral nucleus tractus solitarii, nerve cell bodies exhibiting both radioautographic labeling and immunostaining were detected in all the serotonergic nuclei investigated, namely the nucleus raphe magnus, the ventromedial paragigantocellular nucleus, the nuclei raphe pontis, medianus and dorsalis, the medial lemniscus and the reticulotegmental nucleus of the pons.  

This wave is interpreted as reflection of medial lemniscal activity; so Pgz-Fz derivations make possible the isolated recording of the subcomponent N13b (medial lemniscus, or cuneate nucleus), without overlap with N13a (dorsal horn) - as do neck-to-scalp recordings-; and without the considerable artifacts known from farfield recordings.  

A series of phasic hyperpolarizations repeated with the spindle rhythm appeared in response to single shocks to the medial lemniscus or spontaneously.  

STT units were identified by their antidromic response to stimulation in the contralateral ventrobasal thalamus or medial lemniscus (mean conduction velocity: 18-20 m/sec).  

Somatosensory evoked potentials to median nerve stimulation were recorded in the medial lemniscus, VPL of thalamus and the primary somatosensory cortex. It arises below the level of the thalamus, being very likely generated by the afferent volley in the medial lemniscus, and is seen in the surface-recorded response as the early component P8 (corresponding to P15 in the human)..  

Post-mortem histological analysis revealed that buspirone-treated rats reduced alcohol consumption by 83% if THP had been microinjected into substantia nigra; by 60% if given in the nucleus accumbens-preoptic area; and by 34% when injected into the medial lemniscus-zona incerta.  

The result indicates that chronic alcoholics with spasticity have conduction disturbance in the posterior column and/or the medial lemniscus, which is considered to be due to alcoholic myelopathy and/or a brainstem lesion..  

These DA neurons were characteristically scattered among and medial to the fibers of the medial lemniscus, and a few could be observed as far caudally as the pedunculopontine nucleus.  

Evoked potentials (EPs) were recorded in the caudate nuclei and the nuclei of dorsal columns of the spinal cord to stimulation of the forelimb against the background and after unilateral elimination of the medial lemniscus.  

Evoked responses to peripheral stimulation were recorded in the medial lemniscus, sensory thalamus (ventral posterior lateral nucleus, caudal division, VPLc) and somatosensory cortex. Simultaneous recordings were made from the cortex and either the medial lemniscus or VPLc. Cortical evoked responses to central stimulation of effective sites in either the medial lemniscus or VPLc were decreased during, but not before, the onset of movement.  

In addition, some cells of zone B3 invade the fiber bundles of the medial lemniscus.  

Far-field components P13-P14, which are presumably generated in the medial lemniscus, were not significantly modified.  

This patient, the first so reported, demonstrates the anatomic separation of spinothalamic and dorsal column/medial lemniscus sensory modalities in the human thalamus..  

Evoked activity of sensorimotor cortical neurones in response to stimulation of the pyramidal tract, medial lemniscus and reticular nucleus of the midbrain tegmentum; driving reaction of cortical neurones at stimulation of these brain structures of growing frequency, and conditioned reflexes elaborated by combination of direct stimulation of the sensorimotor cortex and electrocutaneous stimulation were studied in awake nonimmobilized rabbits.  

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