ISSN:
1432-1106
Keywords:
Cerebellum
;
Cerebral cortex
;
Mossy fibers
;
Climbing fibers
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The patterns of convergence of nerve and cortical inputs representing the forelimb and hindlimb were studied in Purkyně cells of the cat. The most important inputs to Purkyně cells of the pars intermedia come from peripheral nerves and the areas of the sensorimotor cortex concerned with the same limb. In lobule V, the forelimb nerve and cortical inputs are dominant, while in lobules III and IV the hindlimb inputs are dominant. Lobules IVa–Va represent a zone of hindlimb-forelimb overlap, with the nerve and cortical inputs making parallel transitions from the hindlimb dominance of IVa to the forelimb dominance of Va. Furthermore, within the nerve and cortical projections to the pars intermedia, mossy fiber and climbing fiber systems have similar projection patterns. In addition to the hindlimb-forelimb overlap in lobules IVa–Va, nearly half (44%) of the Purkyně cells throughout lobules III, IV, and V of the pars intermedia respond with weak or moderate responses to cortical or nerve inputs from the non-dominant limb, some of which are clearly important physiologically. By pairing stimuli to nerve and cortex, it was shown that these two inputs converge onto single inferior olive neurons for the climbing fiber system, whereas the nerve and cortical inputs have separate mossy fiber-granule cell pathways, finally converging onto the Purkyně cell. For both the mossy fiber and climbing fiber systems, the nerve and cortical inputs appear to be transmitted most efficiently through the cerebellar cortex when the two inputs arrive simultaneously at the cerebellar cortex and inferior olive, respectively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00238316
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