Magnocellular Nucleus Of Lateral Hypothalamus

The LHA contained 60% of MCH neurons and 81% of H/O neurons, and the same five LHA regions contained the vast majority of MCH (87%) or H/O (93%) neurons present within the LHA: namely the LHA dorsal region (LHAd: 31% of H/O; 38% of MCH), suprafornical region (LHAs: 28% of H/O; 11% of MCH), ventral region medial zone (LHAvm: 15% of H/O; 16% of MCH), juxtadorsomedial region (LHAjd: 14% of H/O and MCH) and magnocellular nucleus (LHAm: 5% of H/O; 7% of MCH).  

In one subset of rats transcardial perfusion with India ink was used to estimate the degree of ischemia produced during MCAO/CCAO in the SON, lateral magnocellular nucleus of the PVN (PVL), caudoputamen (CP), and frontoparietal cortex (COR).  

In the diencephalon, the magnocellular nucleus, the suprachiasmatic nucleus, the posterior tuberculum, and the ventrolateral and lateral thalamic nuclei were moderately to densely innervated with ghrelin-containing fibers.  

Additional afferents reach the inferior lobe from the nucleus glomerulosus, nucleus suprachiasmaticus, dorsal and central posterior thalamic nucleus, nucleus lateralis valvulae, magnocellular part of the magnocellular nucleus of the preoptic region, caudal nucleus of the preglomerular region, posterior tuberal nucleus, area dorsalis of the telencephalon, and a tegmental nucleus (T2).  

In males, dense alpha(2)-receptors were observed in the song system (Area X, the high vocal center (HVc), the lateral portion of the magnocellular nucleus of the anterior neostriatum, and the robust nucleus of the archistriatum). In contrast, in females neither the lateral portion of the magnocellular nucleus of the anterior neostriatum nor the HVc could be identified based on alpha(2)-receptor binding.  

Two populations of HST-immunoreactive neurons were localized in the anterior preoptic area and the dorsal magnocellular nucleus of the hypothalamus.  

Varicose axons formed tight pericellular arrays in the neocortex, mainly the ectosylvian gyrus, and in the lateral septum and medullar magnocellular nucleus.  

The lateral magnocellular nucleus of the anterior neostriatum (lMAN) is necessary for both initial learning of vocal patterns in developing zebra finches, as well as for modification of adult song under some circumstances.  

Significant immunoreactivity was observed in auditory nuclei, including the nucleus mesencephalicus lateralis pars dorsalis, the thalamic nucleus ovoidalis, field L, the shelf of the high vocal center (HVC), and the cup of the nucleus robustus archistriatalis (RA), as well as in song control nuclei, including the HVC, RA, the lateral magnocellular nucleus of the anterior neostriatum, and the dorsomedial nucleus (DM) of the intercollicular complex.  

NE turnover rates changed significantly over development in all six VCN [ nucleus interfacialis (Nlf), high vocal center (HVC), nucleus robustus of the archistriatum (RA), dorsomedial portion of the intercollicular nucleus (DM), Area X of the parolfactory lobe, and lateral portion of the magnocellular nucleus of the anterior neostriatum (IMAN)]; one AN [ nucleus mesencephalicus lateralis pars dorsalis (MLd)], and one HN [ preopticus anterior (POA)].  

The medial magnocellular nucleus of the anterior neostriatum (mMAN) is a small cortical nucleus which was previously identified as a component of the neural circuitry controlling vocal behavior in songbirds based on its efferent connection to the High Vocal Center (HVC), a major song control nucleus (Nottebohm et al. Inputs to DMP were distributed throughout the dorsal archistriatum and included the area that receives a projection from the parvicellular shell region of the lateral magnocellular nucleus of the anterior neostriatum, a song control nucleus, as well as the dorsal portion of the robust nucleus of the archistriatum, the motor-cortical output of the song control system.  

In the mesencephalon, the tectum and the magnocellular nucleus of the torus semicircularis contained many positive cells.  

None of the telencephalic vocal control nuclei had appreciable numbers of cells immunoreactive for aromatase within their boundaries, with the possible exception of a group of cells that may correspond to the medial part of the magnocellular nucleus of the neostriatum.  

Finally PMO-VI is mainly present in the oriens layer and in the stratum radiatum of the hippocampus formation, in the supraoptic and lateral magnocellular nucleus of the hypothalamus, in the mesencephalic trigeminal nucleus, in the ventral auditory nucleus and in the facial nucleus of the brain stem as well as in red nucleus of the reticular formation and in the Purkinje layer of the cerebellar cortex.  

Numerous large and medium-sized neurons contain vasopressin messenger ribonucleic acid in the paraventricular nucleus, supraoptic nucleus, and accessory magnocellular nucleus. Oxytocin messenger ribonucleic acid is found in the supraoptic nucleus, paraventricular nucleus, accessory magnocellular nucleus and, less frequently, in neurons of the lateral hypothalamus.  

The neostriatum showed a rather complex pattern of staining with unstained areas, such as the magnocellular nucleus of the anterior neostriatum, and other parts intensely stained, especially in its caudal region.  

There was a sex difference in TH immunoreactivity within song-control nuclei: males had light to moderate staining in all three cortical nuclei examined, whereas females had little or no label in corresponding areas [ lateral magnocellular nucleus of the anterior neostriatum (IMAN), higher vocal center (HVC), and robust nucleus of the archistriatum (RA)].  

Positive cells filled an area extending between the subincertal nucleus in the dorsal part, the ventromedial hypothalamic nucleus in the ventral part, and the internal capsule and the magnocellular nucleus of the lateral hypothalamus in the lateral part.  

In contrast, the robust nucleus of the archistriatum and the magnocellular nucleus of the anterior neostriatum showed low levels of binding in comparison with the surrounding tissue.  

The ventromedial nucleus of the hypothalamus and dorsolateral magnocellular nucleus, respectively, contained moderate and heavy concentrations of enkephalin-IR cells.  

The main results concerning the neurohormones and the carrier proteins are the following: a significant decrease in the number of the oxytocin- (OXY) like immunoreactive neurons of the medial and lateral parvocellular nuclei; a decrease in the vasopressin- (VAS) like immunoreactive neurons of the medial and lateral parvocellular nuclei and also of the medial magnocellular nucleus; a decrease in the neurophysin- (NRP) like immunoreactive neurons of the lateral parvocellular nucleus.  

In particular, a high percentage of labeled cells was observed in the lateral septum, the nucleus accumbens, the preoptic medial nucleus, the supraoptic nuclei, the anterior medial hypothalamus, the paraventricular magnocellular nucleus, the caudal parts of the lateral hypothalamus and in the whole tuberal and infundibular area.  

Many other discrete regions contained different densities of labeled perikarya: the medial preoptic nucleus, paraventricular nucleus, retrochiasmatic area, arcuate nucleus, lateral magnocellular nucleus, and the posterior area.  

The neurons were large and they were found exclusively in the posterior hypothalamus, as in the rat, but in the guinea pig they were more numerous and distributed more widely in thin layer around the posterior mammillary nucleus, scattered between and within the medial mammillary nuclei, and in a dense cell cluster emerging from the caudal magnocellular nucleus and extending to the medial preoptic area.  

The spontaneous activity and the inputs to the medial basal hypothalamus (MBH) following dorsal raphe (DR), spinal tract of the trigeminal nerve (SpV), medial lemniscus (ML), reticular lateral magnocellular nucleus ( RLM ) and acoustic (Ac) stimulation and the effects of morphine and the opioid antagonist, naloxone, on these inputs, were investigated in morphine-naive and morphine-dependent animals.  

HDCI cell bodies were concentrated in the posterior hypothalamic area, such as in the tuberal magnocellular nucleus, caudal magnocellular nucleus, posterior hypothalamic nucleus and lateral hypothalamus just lateral to the fasciculus mammillothalamicus at the level of the posterior hypothalamic nucleus.  

HRP-positive neurons were found ipsilaterally and mainly in the following structures: the infralimbic cortex (area 25), septal area including the nucleus of the diagonal band, nucleus accumbens, olfactory tubercle, medial and lateral preoptic areas, preoptic magnocellular nucleus, substantia innominata, bed nucleus of the stria terminalis and the central amygdaloid nucleus. Of these, neurons of the nucleus accumbens, olfactory tubercle, preoptic magnocellular nucleus and substantia innominata were preferentially labeled when the enzyme was deposited in the lateral part of the LHA..  

Other areas containing hormone-concentrating cells are the medial preoptic area, nucleus periventricularis magnocellularis of the hypothalamus, dorsal infundibular layers, dorsomedial thalamus, lateral septum, magnocellular nucleus of the anterior neostriatum, periventricular medial neostriatum, nucleus taeniae of the archistriatum, and ventral paleostriatum augmentatum.  

[ View All ]