title: A direct input from amygdaloid complex to caudate nucleus of the rat.
abstract: Spontaneous unit activity was recorded from the caudate nucleus in rats anesthetized with urethane. Amygdaloid nucleus stimulation altered the spontaneous activity of 51 units (65% of the population tested); 23 units (29%) showed an increase and 28 (36%) a decrease of discharge rate. Moreover, 25 units (32%) responded to stimulation with stimulus-locked spikes. Post-stimulus time histograms revealed 7 patterns of response to amygdaloid stimulation. In 4 groups of cells, stimulus-locked spikes occurred followed by alteration of spontaneous discharge rate. In another 2 groups there was a change of spontaneous discharge without stimulus-locked spikes and in the final group no effect occurred. The possibility of mono-, oligo-, and polysynaptic connections from amygdaloid nuclear complex to caudate nucleus was discussed. It was suggested that an amygdalofugal connection to basal ganglia may provide a pathway whereby activity of the limbic system may exert a modulatory influence on somatic motor mechanisms.
mesh_terms: D000201:Activation Analysis; D000679:Amygdala / Q000502:physiology*; D000818:Animals; D002415:Cats; D002421:Caudate Nucleus / Q000502:physiology*; D002685:Chiroptera; D004558:Electric Stimulation; D005071:Evoked Potentials; D000882:Haplorhini; D009474:Neurons / Q000502:physiology; D051381:Rats; D011930:Reaction Time / Q000502:physiology; D009435:Synaptic Transmission