[Effect of stimulation of gigantocellulars reticular nucleus on the spontaneous and evoked activities of cerebellar Purkinje cells in the rat].
In anesthetized and paralyzed rats, the effect of stimulation of Gigantocellulars Reticular Nucleus (Gi) on spontaneous and evoked simple spike discharges of cerebellar Purkinje cells (PCs) was examined. The result were as follows: (1) Stimulation of Gi elicited either inhibitory or excitatory effect on spontaneous simple spikes of PCs with latency less than 20 ms, being inhibitory in the most cases. The inhibitory responses lasted for 40-100 ms, while the excitatory ones were sometimes longer than 200 ms; (2) Injection of 5-HT2 receptor antagonist methysergide could reversibly attenuate or block the inhibitory effect of Gi stimulation on spontaneous simple spike discharges of PCs; (3) The evoked simple spike responses of PCs elicited by stimulating the contralateral cerebral sensorimotor cortex could be markedly suppressed or potentiated by the conditioning Gi stimulation. The results demonstrated that Gi-cerebellar pathways exists, with some fibers being serotonergic. Gi-cerebellar afferent fibers may have certain modulatory effects on PCs through synaptic and/or non-classical chemical synaptic transmission. The Gi-cerebellar afferent fiber projection may play important roles in some cerebellar functions, such as regulating myotonia and posture.
Department of Biology, Nanjing University.
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Zhang
J J
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Wang
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Wang
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Chen
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Chen
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Yu
D000818:Animals; D002525:Cerebellar Cortex / Q000166:cytology / Q000502:physiology*; D004558:Electric Stimulation; D004594:Electrophysiology; D005260:Female; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology; D008784:Methysergide / Q000494:pharmacology; D011690:Purkinje Fibers / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012154:Reticular Formation / Q000502:physiology*
D008784:Methysergide