Long-term synaptic changes induced in the cerebellar cortex by fear conditioning.
To better understand learning mechanisms, one needs to study synaptic plasticity induced by behavioral training. Recently, it has been demonstrated that the cerebellum is involved in the consolidation of fear memory. Nevertheless, how the cerebellum contributes to emotional behavior is far from known. In cerebellar slices at 10 min and 24 hr following fear conditioning, we found a long-lasting potentiation of the synapse between parallel fibers and Purkinje cells in vermal lobules V-VI, but not in the climbing fiber synapses. The mechanism is postsynaptic, due to an increased AMPA response. In addition, in hotfoot mice with a primary deficiency of the parallel fiber to Purkinje cell synapse, cued (but not contextual) fear conditioning is affected. We propose that this synapse plays an important role in the learned fear and that its long-term potentiation may represent a contribution to the neural substrate of fear memory.
Sacchetti
Benedetto
B
Rita Levi-Montalcini Center for Brain Repair, Department of Neuroscience, University of Turin, Corso Raffaello 30, I-10125 Turin, Italy.
Scelfo
Bibiana
B
Tempia
Filippo
F
Strata
Piergiorgio
P
D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001522:Behavior, Animal; D002525:Cerebellar Cortex / Q000166:cytology / Q000502:physiology*; D003213:Conditioning, Psychological / Q000502:physiology*; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D005239:Fear; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000494:pharmacology; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D009043:Motor Activity / Q000502:physiology; D010147:Pain Measurement; D018408:Patch-Clamp Techniques / Q000379:methods; D011689:Purkinje Cells / Q000502:physiology; D011810:Quinoxalines / Q000494:pharmacology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000502:physiology; D012153:Retention, Psychology / Q000502:physiology; D013569:Synapses / Q000502:physiology*; D013997:Time Factors
D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D011810:Quinoxalines; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D007608:Kainic Acid