ABSTRACT
Long-term potentiation of synaptic transmission (LTP) is a long-lasting amplification of synaptic strength and seems to provide a mechanism for learning which suggests that storage of memory resides in the strengthening of synaptic contacts. This chapter discusses the biochemical, electrophysiological, and behavioral effects of muscarinic receptor activation which form the currently accepted mechanistic basis of the enhancement of LTP. It is possible that more than one muscarinic receptor subtype is involved in modulation of LTP. The chapter summarizes the activation of muscarinic receptors that results both in excitatory and inhibitory effects. Since LTP has been proposed as a principle for storage of memory, it is of interest to consider the effects of muscarinic agents on learning and memory. It is clear that in most paradigms, the operant tasks require awareness of cues for discrimination, sensitivity for reinforcement, and locomotion, which are all modulated by muscarinic receptor ligands.
