Rapamycin-treated and -untreated/trained/probed mice are the main part of the experiment considering retrieval and acquisition or consolidation of spatial memory.
Six hours following euthanasia hippocampi were extirpated and used for evaluation of mTOR activity as represented by hippocampal levels of S6 protein and its phosphorylated active form (phospho S6 protein, S240,244), a read out of mTOR complex 1 activity.
Mice given i.p. rapamycin learned the task of the MTM but failed at the probe trial, showing absence of the phosphorylated active form of S6 protein, indicating inhibition of mTOR activity.
Herein, impairing effects of rapamycin on retrieval but not on acquisition or consolidation of spatial memory are shown. Deficient memory retrieval was paralleled by inhibition of mTOR complex 1 activity. The current study extends knowledge on rapamycin in memory mechanisms and challenges work on deeper insights into the role of mTOR in different phases of memory formation and retrieval.