Figure 7.

(A) Average hippocampal and cerebellar LFPs during early (5th CR) and late (8/9 CRs) theta-contingent trace eyeblink learning. T+ LFPs (blue) display consistent short-latency onset of robust and rhythmic theta oscillations that are precisely time-locked to the CS and US occurrences. T− LFPs (red) are notably less organized at theta frequency across trials and days. (B) Hippocampo-cerebellar crosscorrelograms during the stimulus-free trace interval for early and late theta-contingent trace eyeblink learning show rhythmic, anti-phasic, synchronization of hippocampus and both cerebellar regions at theta frequency during T+ (blue) and not T− (red) trace periods.