Projections of the sensorimotor cortex to the basilar pontine nuclei in the rat: an autoradiographic study

Mihailoff, Gregory A.; Burne, Richard A.; Woodward, Donald J.

doi:10.1016/0006-8993(78)90867-3

Cited by 81 publications

(55 citation statements)

References 10 publications

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“…The cortical projection to the ipsilateral pons from the forelimb area in all groups examined showed the typical topographical innervation pattern as described earlier (Mihailoff et al, 1978;Wiesendanger and Wiesendanger, 1982;Rouiller et al, 1993;Panto et al, 1995). Labeled fibers running in the cerebral peduncle over the basilar pons left the peduncle ventrally and formed typical termination fields.…”

Section: Corticopontine Projectionmentioning

confidence: 60%

“…Independent of the antibody treatment and the lesion, most of the labeled fibers were situated in the medial half of the cerebral peduncle, whereas only a minor part was seen in the lateral half, as described earlier (Mihailoff et al, 1978;Kosinski et al, 1986). The average number of BDApositive fibers at midpontine level was 5280 (Ϯ336 SEM; n ϭ 24) for the animals traced by iontophoretic injections and was almost identical to the number in the pressure-injected group (5210 Ϯ 355 SEM; n ϭ 26).…”

Section: Tracingmentioning

confidence: 62%

“…These new contralateral terminations were specific for the forelimb areas, thus mirroring the ipsilateral side, which receives a somatotopic projection from the motor cortex ending in a typical four columnar innervation pattern (Mihailoff et al, 1978;Wiesendanger and Wiesendanger, 1982;Rouiller et al, 1993;Panto et al, 1995). In agreement with earlier studies, a very minor contralateral projection was also found in the normal animals.…”

Section: The Monoclonal Antibody In-1 Enhances Corticorubral and Cortmentioning

confidence: 99%

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Functional Recovery and Enhanced Corticofugal Plasticity after Unilateral Pyramidal Tract Lesion and Blockade of Myelin-Associated Neurite Growth Inhibitors in Adult Rats

et al. 1998

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After a lesion of the mature CNS, structural plasticity and functional recovery are very limited, in contrast to the developing CNS. The postnatal decrease in plasticity is correlated in time with the formation of myelin. To investigate the possible role of an important myelin-associated neurite growth inhibitor (NI-250; IN-1 antigen), one pyramidal tract of adult Lewis rats was lesioned (pyramidotomy), and the rats were treated with the antibody IN-1, a control antibody, or no antibody. Functional recovery was studied from postoperative day 14 until day 42 using a food pellet reaching task, rope climbing, and a grid walk paradigm. The corticofugal projections to the red nucleus and basilar pontine nuclei were analyzed after survival times of 2 and 16 weeks.Treatment with the monoclonal antibody IN-1 resulted in almost complete restoration of skilled forelimb use, whereas all the control groups showed severe and chronic impairments. This functional recovery was paralleled by sprouting of the corticorubral and the corticopontine fibers across the midline, thus establishing a bilateral, anatomically specific projection. Key words: structural plasticity; rat reaching; motor function; motor system; nucleus ruber; pons; corticospinal tract; injuryFunctional and anatomical repair of the injured adult C NS is very limited (for review, see Donoghue, 1995Donoghue, , 1997Schwab and Bartholdi, 1996). In contrast, neuroanatomical plasticity, or the restructuring of neural connections in response to lesions of the CNS, is a well documented phenomenon in the neonatal age group. After unilateral neonatal pyramidotomy in rodents, corticoefferent fibers from the same side as the lesion were found to cross the midline to form new connections with medullary nuclei and to descend to spinal cord levels . Evidence that new neural connections occur after perinatal brain damage in children is supported by several clinical studies (Farmer et al., 1991;C arr et al., 1993;C ao et al., 1994). Structural neuroplasticity is thought to play an essential role in recovery of function, because animals sustaining C NS lesions at a young age are known to recover much better than those sustaining similar lesions at maturity (Kennard, 1936(Kennard, , 1938Whishaw and Kolb, 1988;Armand and Kably, 1993).The lack of large scale remodeling after adult C NS lesions is not well understood, but may be attributable to several reasons, including a limitation of adult neuronal growth potential, a lack or decrease in trophic factors or guidance molecules, or the presence of growth inhibitory molecules. In this regard, limits on the capacity for mature CNS plasticity may be similar to those recently identified for CNS regeneration, for which inhibitory signals present on CNS myelin have been shown to play a crucial role (for review, see Schwab and Bartholdi, 1996). These specific proteins (NI-35 and NI-250) induce long-lasting growth cone collapse and inhibition of neurite growth in vitro (Caroni and Schwab, 1988a;Bandtlow et al., 1990). Neutralization by the s...

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Section: Corticopontine Projectionmentioning

confidence: 60%

Section: Tracingmentioning

confidence: 62%

Section: The Monoclonal Antibody In-1 Enhances Corticorubral and Cortmentioning

confidence: 99%

See 1 more Smart Citation

Functional Recovery and Enhanced Corticofugal Plasticity after Unilateral Pyramidal Tract Lesion and Blockade of Myelin-Associated Neurite Growth Inhibitors in Adult Rats

et al. 1998

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“…For all animal groups, most of the BDA-positive fibers were situated in the medial half of the cerebral peduncle, whereas only a few were seen in the lateral half, as described earlier for the projections from the caudal forelimb area of the motor cortex (Mihailoff et al, 1978;Kosinski et al, 1986). The number of labeled fibers within the cerebral peduncle did not vary significantly among the groups, although fewer BDAlabeled fibers tended to be in the animals lesioned at P2, for both the lesioned as well as the unlesioned CST (6181 Ϯ 1068 SEM, n ϭ 6, for the lesioned CST and 4628 Ϯ 433 SEM, n ϭ 6, for the unlesioned CST), compared with the adult lesioned (8075 Ϯ 1548 SEM, n ϭ 6) or unlesioned animals (7029 Ϯ 583 SEM, n ϭ 6).…”

Section: Bda Injection Sitementioning

confidence: 80%

Compensatory Sprouting and Impulse Rerouting after Unilateral Pyramidal Tract Lesion in Neonatal Rats

et al. 2000

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After lesions of the developing mammalian CNS, structural plasticity and functional recovery are much more pronounced than in the mature CNS. We investigated the anatomical reorganization of the corticofugal projections rostral to a unilateral lesion of the corticospinal tract at the level of the medullary pyramid (pyramidotomy) and the contribution of this reorganization and other descending systems to functional recovery.Two-day-old (P2) and adult rats underwent a unilateral pyramidotomy. Three months later the corticofugal projections to the red nucleus and the pons were analyzed; a relatively large number of corticorubral and corticopontine fibers from the lesioned side had crossed the midline and established an additional contralateral innervation of the red nucleus and the pons. Such anatomical changes were not seen after adult lesions.Intracortical microstimulation of the primary motor cortex with EMG recordings of the elbow flexor muscles were used to investigate possible new functional connections from the motor cortex of the pyramidotomy side to the periphery. In rats lesioned as adults, stimulation of the motor cortex ipsilateral to the pyramidotomy never elicited EMG activity. In contrast, in P2 lesioned rats bilateral forelimb EMGs were found. EMG latencies were comparable for the ipsilateral and contralateral responses but were significantly longer than in unlesioned animals. Transient inactivation of both red nuclei with the GABA receptor agonist muscimol led to a complete loss of these bilateral movements. Movements and EMGs reappeared after wash-out of the drug. These results suggest an important role of the red nucleus in the reconnection of the cortex to the periphery after pyramidotomy.

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“…One subcortical pathway goes to the basal ganglia, and the other goes to the cerebellum via the pontine nuclei (1)(2)(3)(4). The efferent terminals from the basal ganglia and cerebellum remain largely distinct in the thalamus and their thalamic targets project to nonoverlapping regions of the motor cortex (5).…”

mentioning

confidence: 99%

Basal ganglia and cerebellum receive different somatosensory information in rats.

Mercier

Legg

Glickstein

1990

Proc. Natl. Acad. Sci. U.S.A.

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There are two great subcortical circuits that relay sensory information to motor structures in the mammalian brain. One pathway relays via the pontine nuclei and cerebellum, and the other relays by way of the basal ganglia.We studied the cells of origin of these two major pathways from the posteromedial barrel subfield ofrats, a distinct region ofthe somatosensory cortex that contains the sensory representation of the large whiskers. We itjected tracer substances into the caudate putamen or the pontine nuclei and charted the location of retrogradely filled cortical cells. In preliminary studies, we used double-labeling techniques to determine whether the cells of origin of these two pathways send axon collaterals to other subcortical targets. Lamina V of the rat posteromedial barrel subfield contains two distinct populations of subcortically projecting neurons, which are organized into distinct sublaminae. Corticopontine cells are located exclusively in sublamina Vb, the deeper of two sublaminae revealed by cytochrome oxidase staining. Corticostriate cells are located almost exclusively in the more superficial sublamina Va. Experiments using double-labeling fluorescent tracers demonstrate that about one-quarter of the corticopontine cells send a collateral branch to the superior colliculus. Other studies have shown that cells in Vb are activated at very short latency after vibrissal stimulation; hence, they would seem to be an appropriate relay for the rapid transmission of sensory information to the cerebellum for use in sensory guidance of movement.Sensory areas of the cerebral cortex are connected to motor areas by way of corticocortical circuits and two prominent subcortically directed pathways. One subcortical pathway goes to the basal ganglia, and the other goes to the cerebellum via the pontine nuclei (1-4). The efferent terminals from the basal ganglia and cerebellum remain largely distinct in the thalamus and their thalamic targets project to nonoverlapping regions of the motor cortex (5). Do the basal ganglia and the cerebellum receive inputs from the same or a different population of sensory cortical cells?The great majority of the cells in the sensory cortex that project to these two motor systems are located in lamina V of the cerebral cortex (2, 6-8). Lamina V may be divided into two sublaminae: a superficial sublamina Va and a deep sublamina Vb, which differ in a number of important respects. In mice, lamina Vb receives direct input from the somatosensory relay nucleus in the thalamus; Va does not (9). Stimulation of the appropriate whisker in rats activates cells in sublamina Vb at a latency that is as short as that for activating cells in lamina IV, the principal target of incoming thalamic fibers (10). In contrast, cells in Va respond at much longer latency to such stimulation. Cells in Va stain palely when tested for the presence of the metabolic enzymes cytochrome oxidase or succinic dehydrogenase (11). Cells in sublamina Vb stain far more densely, suggesting that they are capable ofh...

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Projections of the sensorimotor cortex to the basilar pontine nuclei in the rat: an autoradiographic study

Cited by 81 publications

References 10 publications

Functional Recovery and Enhanced Corticofugal Plasticity after Unilateral Pyramidal Tract Lesion and Blockade of Myelin-Associated Neurite Growth Inhibitors in Adult Rats

Functional Recovery and Enhanced Corticofugal Plasticity after Unilateral Pyramidal Tract Lesion and Blockade of Myelin-Associated Neurite Growth Inhibitors in Adult Rats

Compensatory Sprouting and Impulse Rerouting after Unilateral Pyramidal Tract Lesion in Neonatal Rats

Basal ganglia and cerebellum receive different somatosensory information in rats.

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