[Demonstration of the excitatory effect of the thalamo-subthalamic efferent from the parafascicular nucleus].
The synaptic effect of the projection from an intralaminar thalamic structure, the parafascicular nucleus, to the subthalamic nucleus was investigated through extracellular recordings of subthalamic unit activities. Electrical stimulation of the parafascicular nucleus caused a complex response with two successive excitatory phases. The first excitation was assumed to be monosynaptically driven since it was not affected by pallidal lesion or transsection of the internal capsule. Pharmacological activation of the parafascicular neurons through microinjections of carbachol elicited a prolonged increase in the subthalamic discharge rate. These results suggest that the intralaminar parafascicular nucleus contributes to the activation of subthalamic neurons.
Féger
J
J
Laboratoire de Pharmacologie, Faculté des Sciences pharmaceutiques et biologiques, Université René-Descartes, Paris.
Mouroux
M
M
D000818:Animals; D004558:Electric Stimulation; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009476:Neurons, Efferent / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D013787:Thalamic Nuclei / Q000502:physiology*
Mise en évidence de l'effet excitateur de l'efférence thalamo-subthalamique issue du noyau parafasciculaire.