INTRODUCTION +1190Despite the large number of studies on all aspects of the hippocampus, the function of this structure is still an enigma. In our view multidisciplinary studies of input-output relations integrated with behavioral analytical inves tigations hold the greatest promise for a solution to this problem. Therefore, this review is dedicated to the basic physiology of the hippocampus seen as a group of input-output subsystems.The first several sections deal with the functional anatomy and electro physiology. This subject receives more intensive treatment in those sections where recent anatomical data obtained with tracer techniques have pro vided signifi cant advances. In the second half of the review, hippocampal behavior correlates are dealt with. The insight of the authors into these aspects is here given precedence over a detailed review of the extensive literature. The treatment of transmitters and pharmacological aspects is omitted here in view of the recent comprehensive review of . Several reviews of the physiology of the hippocampus have been published. A classic is that of Brodal (39). The last physiological review is that of Green (86). Since then there have appeare d reviews on the phar macology of the electrical activity of the hippocampus (196); on the physi ology of cellular processes (189); and on behavioral correlates of hippocam pal function (4, 63, 1l3, 141). The comprehensive book of Isaacson (103) gives a survey of the limbic system. A collection of papers on several aspects of hippocampal structure and physiology, its relation to behavior, its devel opment and neuroendocrinology has been edited recently by Isaacson & Pribram (104). A book covering the Russian literature on the hippocampus has also appeared (76). 185 0066-4278/78/0301-0185$0 1.00 Annu. Rev. Physiol. 1978.40:185-216. Downloaded from www.annualreviews.org Access provided by University of British Columbia on 11/25/14. For personal use only.