X-Message-Number: 12678 Date: Sat, 30 Oct 1999 18:31:42 -0400 From: Jan Coetzee <> Subject: hippocampal participation Reversible neural inactivation reveals hippocampal participation in several memory processes G. Riedel1, 2, 6, J. Micheau3, 6, October 1999 Volume 2 Number 10 pp 898 - 905 Nature Neuroscience Studies of patients and animals with brain lesions have implicated the hippocampal formation in spatial, declarative/relational and episodic types of memory. These and other types of memory consist of a series of interdependent but potentially dissociable memory processes encoding, storage, consolidation and retrieval. To identify whether hippocampal activity contributes to these processes independently, we used a novel method of inactivating synaptic transmission using a water-soluble antagonist of AMPA/kainate glutamate receptors. Once calibrated using electrophysiological and two-deoxyglucose techniques in vivo, drug or vehicle was infused chronically or acutely into the dorsal hippocampus of rats at appropriate times during or after training in a water maze. Our findings indicate that hippocampal neural activity is necessary for both encoding and retrieval of spatial memory and for either trace consolidation or long-term storage. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=12678