A dynamic model of learning in the septo-hippocampal system

Gluck and Myers (Hippocampus 3 (1993) 491-516) modeled the hippocampus as a n auto-encoder; Myers et al. (Neurobiol. Learning Memory 66 (1996) 51-66) a rgued that the cholinergic input from medial septum modulates learning rate in this auto-encoder. Neurophysiological evidence suggests the hippocampus self-regulates septal acetylcholine release in response to novel stimuli ( Hasselmo and Schnell, J. Neurosci. 14 (1994) 3898-3914). We have extended o ur earlier model of septohippocampal modulation to include such a feedback loop. The resulting dynamic model learns faster and better than the earlier version on phenomena such as blocking and shift reversal. It can also be a pplied to data regarding the effects of the anticholinergic drug scopolamin e. (C) 2000 Elsevier Science B.V. All rights reserved.