Attenuating the effect of Ghrelin on memory storage via bilateral reversible inactivation of the basolateral amygdale

Previous studies have shown that Ghrelin increases memory retention. They have also indicated that amygdale is involved in memory storage. The present study examined the role of basolateral amygdala (BLA) in Ghrelin-induced retention improvement, using reversible inactivation of this region with lidocaine. Rats were bilaterally implanted with cannulae at the BLA. One week later, they received intra-BLA injection of lidocaine, saline or Ghrelin with 5 min interval immediately after training. 24–72 h after training, step-through latency (STL) was measured as learning and memory index. The results showed that injection of Ghrelin into the BLA produced a significant enhancement in retention, which was attenuated by injection of lidocaine into BLA. These finding indicate that the BLA is involved in mediating the memory-modulating effect of Ghrelin.

► In this study we examined the effect of ghrelin on the reversible inactivation of BLA.
► We found that ghrelin effect on improvement of memory is mediated partly by BLA.
► We conclude that ghelin's effect on memory is attenuated by BLA's inactivation effect.
► This study showed that intact BLA is not required for expression of retention.