Selective lesioning of the cholinergic septo-hippocampal pathway does not disrupt spatial short-term memory: a comparison with the effects of fimbria-fornix lesions.

Rats receiving intrahippocampal injections of 192 IgG-saporin (SAP-HPC), fimbria-fornix lesions (FF), or sham control surgeries were tested in a series of delayed matching (DMTP)- and nonmatching (DNMTP)-to-position tasks. The FF group was significantly impaired on a pretrained DNMTP task relative to the control and SAP-HPC groups, which did not differ. All groups then acquired a matching-to- position rule at the same rate, and only the FF group showed a delay-dependent deficit when longer retention intervals were introduced for DMTP testing. Results demonstrate the importance of the fimbria-fornix fiber system in spatial short-term memory but suggest that the cholinergic septohippocampal component of this pathway is not required for successful delayed matching (or nonmatching)-to-position performance. ((c) 2004 APA, all rights reserved)