Cerebellar theta oscillations are synchronized during hippocampal theta-contingent trace conditioning.
The hippocampus and cerebellum are critically involved in trace eyeblink classical conditioning (EBCC). The mechanisms underlying the hippocampal-cerebellar interaction during this task are not well-understood, although hippocampal theta (3-7 Hz) oscillations are known to reflect a favorable state for EBCC. Two groups of rabbits received trace EBCC in which a brain-computer interface administered trials in either the explicit presence or absence of naturally occurring hippocampal theta. A high percentage of robust theta led to a striking enhancement of learning accompanied by rhythmic theta-band (6-7 Hz) oscillations in the interpositus nucleus (IPN) and cerebellar cortex that were time-locked both to hippocampal rhythms and sensory stimuli during training. Rhythmic oscillations were absent in the cerebellum of the non-theta group. These data strongly suggest a beneficial impact of theta-based coordination of hippocampus and cerebellum and, importantly, demonstrate that hippocampal theta oscillations can be used to index, and perhaps modulate, the functional properties of the cerebellum.
Hoffmann
Loren C
LC
Department of Psychology and Center for Neuroscience, Miami University, 90 North Patterson Avenue, Oxford, OH 45056, USA.
Berry
Stephen D
SD
D000818:Animals; D001522:Behavior, Animal; D002525:Cerebellar Cortex; D002531:Cerebellum / Q000502:physiology*; D003214:Conditioning, Classical / Q000502:physiology*; D003215:Conditioning, Eyelid; D006624:Hippocampus / Q000502:physiology*; D007858:Learning; D011817:Rabbits; D013826:Theta Rhythm