Pregnenolone sulfate infused in lateral septum of male rats impairs novel object recognition memory

In the present paper we show for the first time that pregnenolone sulfate (preg-s) impairs rats' memory for novel object recognition when injected in lateral septum (1.2 μm). the effect of preg-s is clearly related to the moment the reagent is administered: if administered shortly after the training phase,or prior to the test phase of the experiment,there is no amnesic effect. it is only amnesic when administered 30 min before training. accordingly,preg-s does not appear to affect the storage of new memories or their retrieval but rather the acquisition itself. based on the described afferences and efferences of lateral septum,we suggest a possible stimulatory effect of preg-s regarding glutamate receptors and/or an inhibitory effect of gabareceptors located in local interneurons or recurrent axon collaterals,both of which have been reported to exist in the aforementioned nucleus. © 2010 by institute of pharmacology polish academy of sciences.