Disruption of cerebellar cortical inhibition in the absence of learning promotes sensory-evoked eyeblink responses.
Theories of cerebellar learning propose that alterations in synaptic plasticity resulting in decreases in cerebellar cortical inhibition and increases in sensory activation of interpositus nuclei underlie the development of adaptively timed conditioned motor responses. The authors found that with concurrent pharmacological disconnection of the cerebellar cortex and intense sensory stimulation in the untrained rabbit, eyeblink responses were generated. Neither sensory stimulation nor disconnection alone generated significant eyeblink responses. These results are consistent with dual plasticity models of cerebellar learning and strongly support the general hypothesis that conditioned responses are the result of strengthening of preexisting connections in the nervous system.
Poulos
Andrew M
AM
Neurosciences Program, Department of Psychology, University of Southern California, Los Angeles, CA 90095-153, USA. apoulos@ucla.edu
Nobuta
Hiroko
H
Thompson
Richard F
RF
D000161:Acoustic Stimulation; D000818:Animals; D001245:Association Learning / Q000502:physiology; D001767:Blinking / Q000187:drug effects / Q000502:physiology*; D002404:Catheterization; D002525:Cerebellar Cortex / Q000187:drug effects / Q000502:physiology*; D018756:GABA Antagonists / Q000494:pharmacology; D008959:Models, Neurological; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D010775:Photic Stimulation; D010852:Picrotoxin / Q000494:pharmacology; D011817:Rabbits
D018756:GABA Antagonists; D010852:Picrotoxin