INVOLVEMENT OF THE OLFACTORY-BULB IN CONSOLIDATION PROCESSES ASSOCIATED WITH LONG-TERM-MEMORY IN RATS

In a daily training paradigm, rats were trained to discriminate betwee n spatially distinct electrical stimulations delivered to one olfactor y bulb. Xylocaine injections were used to disrupt the olfactory bulb f unctioning in the region close to the electrode tips for 1 hr after ea ch training session. The treatment started either just after the sessi on or 2 hr later. When compared with the performance of saline-injecte d rats, the performance of Xylocaine-injected rats was unimpaired exce pt when the treatment started just after the daily session. In that ca se, acquisition of the task was slightly altered, and retention over a 5-day period was dramatically impaired. We therefore concluded that, within about 1 hr following training, the olfactory bulb is engaged in consolidation processes critical for long-term retention of learned o lfactory cues.