The Cholinergic Septo-Hippocampal Pathway, Learning and Memory

This paper summarizes the results of parallel behavioral, neurochemical and pharmacological experiments aimed at studying the role of septo-hippocampal cholinergic neurones in learning and memory processes in mice. A large body of evidence from pharmacological experiments supports the association of central cholinergic mechanisms with many aspects of behavior (De Feudis, 1974) and in particular with information encoding storage and/or retrieval (Deutsch, 1971; Biederman, 1974; Matthies, 1974; Squire and Davis, 1981). The hypothesis that the hippocampus plays a key role in memory processes (Isaacson, 1974) has focussed considerable attention on the possibility that the cholinergic neurones of the septo-hippocampal pathway (Lewis and Shute, 1967) may mediate control on some mechanisms involved in mnemonic function (Routtenberg, 19S4). To circumvent the difficulties deriving from the frequently used approach of pharmacological studies utilising peripheral drug injections which have often generated discordant results on this problem, we have adopted the research strategy of investigating the modulation of learning and memory processes in selected inbred mouse strains combined with direct neurochemical methods to investigate hippocampal cholinergic activity.