title: Pyramidal input to the intracerebellar nuclei of the cat.
abstract: In unanesthetized cats it has been found that pyramidal volleys elicited upon medullary pyramidal tract stimulation were capable of modifying the discharge of 41% of intracerebellar nuclear cells, via pontocerebellar systems impinging predominantly on the lateral cerebellar cortex. The incidence of responsive cells was 80% in the dentate nucleus compared with 10% in the fastigial nucleus, 11% in the anterior and 12% in the posterior division of the interpositus nucleus. The response was in 59% of the cases excitation followed by inhibition, in 30% of the cases a pure excitation and in 11% of the cases a pure inhibition. Excitation, pure or followed by inhibition, had a mean latency of 5.78 ms and a mean duration of 12.21 ms, while inhibition displayed a mean latency of 9.03 ms and a mean duration of 34.64 ms. The possible functional significance of the pyramidal input to the lateral cerebellum is briefly discussed in relation to a possible convergence of pyramidal and associative impulses in single cerebellar neurons.
mesh_terms: D000818:Animals; D001931:Brain Mapping; D002415:Cats; D002525:Cerebellar Cortex / Q000502:physiology; D002529:Cerebellar Nuclei / Q000502:physiology*; D004558:Electric Stimulation; D008526:Medulla Oblongata / Q000502:physiology; D009044:Motor Cortex / Q000502:physiology; D009433:Neural Inhibition; D009474:Neurons / Q000502:physiology; D011149:Pons / Q000502:physiology; D011689:Purkinje Cells / Q000502:physiology; D011712:Pyramidal Tracts / Q000502:physiology*; D009435:Synaptic Transmission