title: Hippocampal AP5 treatment impairs both spatial working and reference memory in radial maze performance in rats.
abstract: The possible involvement of hippocampal N-methyl-d-aspartate (NMDA) receptors in spatial reference and working memory was investigated. Rats were first trained in a four-baited/four-unbaited version of the eight-arm radial maze task in which only predetermined four arms for each rat were baited with a food pellet. After rats reached the learning criterion, their performance was tested under the treatment of a NMDA antagonist, AP5 (d,l-2-amino-5-phosphonopentanoic acid, 20-40nmol), or vehicle into the dorsal hippocampus through the bilaterally implanted guide cannulae. AP5 produced dose-dependent increments on both reference and working memory errors, but did not have any effect on the running speed. Additionally, there were significant correlations between the number of trials to criterion in acquisition and the number of reference and working memory errors induced by AP5 treatment. The results suggest that hippocampal NMDA receptors are involved in both spatial reference and working memory.
authors: Institute of Psychology and Behavioral Neuroscience, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
authors: Kazuo
authors: K
authors: Yamada
authors: Institute of Psychology and Behavioral Neuroscience, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
authors: Makoto
authors: M
authors: Shimizu
authors: Graduate School of Literature and Human Sciences, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors: Kouichi
authors: K
authors: Kawabe
authors: Institute of Psychology and Behavioral Neuroscience, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan. Electronic address: y-ichit@human.tsukuba.ac.jp.
authors: Yukio
authors: Y
authors: Ichitani
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D008570:Memory, Short-Term / Q000187:drug effects*; D008845:Microinjections; D051381:Rats; D065852:Spatial Memory / Q000187:drug effects*
chemical_list: D015763:2-Amino-5-phosphonovalerate
keywords: AP5; Hippocampus; NMDA receptor; Radial maze; Rat; Spatial reference memory; Spatial working memory