Inhibitory Cerebello-Olivary Projections and Blocking Effect in Classical Conditioning
Jeansok J. Kim,
*
David J. Krupa,
Richard F. Thompson
The behavioral phenomenon of blocking indicates that the
informational relationship between the conditioned stimulus and the unconditioned stimulus is essential in classical conditioning. The
eyeblink conditioning paradigm is used to describe a neural mechanism
that mediates blocking. Disrupting inhibition of the inferior olive, a
structure that conveys unconditioned stimulus information
(airpuff) to the cerebellum prevented blocking in rabbits.
Recordings of cerebellar neuronal activity show that the inferior olive
input to the cerebellum becomes suppressed as learning occurs. These
results suggest that the inferior olive becomes functionally inhibited
by the cerebellum during conditioning, and that this negative feedback
process might be the neural mechanism mediating blocking.
Neuroscience Program, University of Southern California, Los
Angeles, CA 90089-2520, USA.
*
To whom correspondence should be addressed. E-mail:
jeansok.kim{at}yale.edu
Present address: Department of Psychology, 2 Hillhouse Avenue,
Yale University, New Haven, CT 06520-8205, USA.
