[Modulatory role of the cerebellar cortex during the classically conditioned nictitating membrane response in rabbit].
Classical conditioning of the rabbit nictitating membrane(NM) response was accomplished by standard delay procedure of paired tone (CS) and airpuff (US) stimuli. Upon reaching a criterion of 90% conditioned responses (CRs) in 3 consecutive blocks, an electrolytic lesion was made at the hemicerebellar VI cortical lobule on the training side. Results showed that the learned response of the dentate-interpositus (D-I) nuclei and the conditioned NM response were completely or almost completely eliminated without affecting the unconditioned response. However, cerebellar cortical lesion performed on animals being over 1 week overtrained produced no effect on CRs and the learned response of the D-I nuclei. Meanwhile, the spontaneous activity of the D-I nuclei during consolidation reduced in frequency as a result of the cortical lesion at the early stage of learning. Our findings indicate that the cerebellar cortex plays a modulatory role in the generation of the conditioned NM response and the development of the learned response of the D-I nuclei at an early stage of learning. With consolidation, the D-I nuclei become free of control from the cerebellar cortex and serve as the essential component of the memory trace for this model system.
Yang
B Y
BY
Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai.
Wang
J
J
Wei
S G
SG
Shen
Y Q
YQ
Wang
P Y
PY
D000818:Animals; D002525:Cerebellar Cortex / Q000502:physiology*; D002529:Cerebellar Nuclei / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology*; D008297:Male; D008568:Memory / Q000502:physiology; D009541:Nictitating Membrane / Q000502:physiology; D011817:Rabbits