Small fusiform and larger lentiform neurons are most abundant in the gracile fasciculus of the cervical and lumbar enlargements and are absent from the cuneate fasciculus and corticospinal tract. 
We demonstrate that the loss of dorsal corticospinal tract (63%) and dorsal column (cuneate fasciculus; 43%) axons in EAE is significantly ameliorated (corticospinal tract: 28%; cuneate fasciculus: 17%) by treatment with phenytoin.
We analyzed nine nervous pathways: corpus callosum, optic tract, internal capsule, spinal tract of the trigeminal nerve, inferior cerebellar peduncle, cerebellar white matter, pyramidal tract, medial longitudinal fasciculus, and cuneate fasciculus. The presence of immunoreactive fibers for proteolipid protein (PLP) in the spinal tract of the trigeminal nerve, medial longitudinal fasciculus and cuneate fasciculus was noted on postnatal day 0. The time required to reach the intensity of myelination of day 42 was day 14 for the cuneate fasciculus, day 21 for the spinal tract of the trigeminal nerve, inferior cerebellar peduncle and medial longitudinal fasciculus, day 28 for the optic and pyramidal tracts, day 35 for the corpus callosum and day 42 for the internal capsule and cerebellar white matter.
We analyzed nine nervous pathways: corpus callosum, optic tract, internal capsule, spinal tract of trigeminal nerve, inferior cerebellar peduncle, cerebellar white matter, pyramidal tract, medial longitudinal fasciculus, and cuneate fasciculus. The onset of the myelination of the spinal tract of the trigeminal nerve, inferior cerebellar peduncle, medial longitudinal fasciculus and cuneate fasciculus was day 7 (postnatal).
In separate tests, the output pulse train was applied to forelimb cutaneous axons of the anesthetized cat; trains of elicited propagating action potentials were recorded extracellularly from individual G1 axons in the cuneate fasciculus.
The cuneate fasciculus also reached degree 4 at 34-36 weeks, but corticospinal tracts and solitary tracts, which exhibited long myelinating phases, were slow and incomplete at 40 weeks.
Similar, though slightly less dense immunoreactivity was observed in the cuneate fasciculus.
Electrophysiologically identified G hair and Ia muscle afferent fibers in the cuneate fasciculus were intraaxonally injected with horseradish peroxidase.
The morphology of single postsynaptic afferent fibers terminating in the feline cuneate nucleus was investigated by using transport of Phasolus vulgaris leucoagglutinin from the cervical spinal cord and intraaxonal injections of horseradish peroxidase into identified postsynaptic fibers in the cuneate fasciculus.
Following unilateral lesions severing the greatest part of the cuneate fasciculus, a considerable decrease of the numbers of labeled cells of the three types was observed caudal and ipsilaterally to the lesion.
After mechanical lesions of the dorsal white matter which severed most of the ipsilateral cuneate fasciculus, the numbers of superficial dorsal horn cells that were labelled from the dorsal reticular nucleus were considerably decreased caudal to the lesion, which suggests that their axons utilize mostly the cuneate fasciculus.
Transganglionic transport of horseradish peroxidase or lectin-conjugated horseradish peroxidase from an application site in the cervical trunk of the glossopharyngeal (IXth cranial) nerve of the rat produced extraperikaryal reaction product characteristic of axon terminal processes in three regions of the brain stem: (1) the nucleus of the tractus solitarius, from approximately 2.5 mm rostral to the obex to approximately 3 mm caudal to the obex; (2) the spinal trigeminal nucleus at the level of obex; (3) the cuneate fasciculus, approximately 3 mm caudal to the obex.
Retrogradely labeled cells in the region of the dorsal column nuclei were located mainly in a shell on the dorsal edge of the cuneate nucleus extending into the white matter of the cuneate fasciculus.
It was found that observed results included little detectable contribution from current spread of the stimulus toward the adjacent structures (dorsal medullary reticular formation and cuneate fasciculus) surrounding the SOL and from retrograde activation of the cerebellar fastigial nucleus.
These figures are very similar to those previously obtained in a sample of primary afferent fibers of the raccoon cervical cuneate fasciculus (L.
Based on segmental and species differences in the presence of this fiber separation, and on prior physiologic and anatomic evidence, we suggest that this form of fiber sorting in the cuneate fasciculus is modality based.
For example, in the human brain there is a dense plexus of substance P-immunoreactive fibres in the cuneate fasciculus.
In transverse sections of the cervical enlargement, stained to reveal degenerating fibers, by far the heaviest loss of axons occurred in the cuneate fasciculus and in the gray matter ipsilateral to the cut dorsal roots.
These values are in the same range as those previously reported for primary afferents of the cuneate fasciculus (Pubols and Pubols, 1973)..
Oblique or vertical processes increase in the cuneate fasciculus from P0 tot P4 but do not appear in the gracile fasciculus until P4.
For all spinal levels studied except C8, degeneration in the medullary cuneate fasciculus was present within two distinct groups. Hence, the dual transverse terminal patterns for cervical fibers in the cuneate nucleus appeared to be related directly to a fiber sorting process that involved the formation of two often separate ascending fiber groups in the cuneate fasciculus.
Axonopathy was severer in the more distal axonal segments, although the cuneate fasciculus was more affected than the gracile fasciculus.
For digits and palm, RF areas of neurons of the cuneate nucleus are approximately 40 and 100 times larger, respectively, than RF areas of primary afferent fibers of the cuneate fasciculus..
In anesthetized, immobilized cats, individual axonal responses to movement of forelimb G hairs were recorded in the ipsilateral cuneate fasciculus at C1-C2 with a glass-insulated tungsten microelectrode.
While no primary wrist joint afferent fibres were recorded in the dorsal columns, their presence was demonstrated by recording single units in the wrist joint nerve which were antidromically activated by microstimulation in the cuneate fasciculus.
In each case, ascending fibers of passage from C4, C6, and C7 in the cuneate fasciculus were organized so that two distinct fiber laminae were present. The organization of primary afferents from one segment into two ascending fiber laminae in the cuneate fasciculus was reflected in a differential termination pattern within both the CN and LCN.
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