State Dependency and Long-Term Potentiation

Abstract

State-dependent learning (SDL) is the acquisition of behavioral outputs within specific environmental contexts. It is a robust phenomenon that has been demonstrated under a variety of conditions using both animal and human subjects. A number of environmental contexts or drug states have been shown to induce this effect. In the present study alcohol was used as the dissociating agent. The SDL effect was examined at the level of a monosynaptic neural circuit in the hippocampus of the rat. Long-term potentiation (LTP) was employed as a measure of SDL. LTP is the long-lasting enhancement of response strength following brief, high frequency activation, and has been used as a memory model. It has been well documented in monosynaptic systems particularly within the hippocampal circuitry as tested in this study. Although strong potentiation effects were not seen in all of the animals tested even those animals showing such effects showed no evidence for an SDL effect within the circuitry examined. The implications of this finding for future research is discussed