Perirhinal N-methyl- d-aspartate and muscarinic systems participate in object recognition in rats

• Published in: Neuroscience letters 2004-02, Vol.356 (3), p.191-194
• Main Authors: Abe, Hiroshi, Ishida, Yasushi, Iwasaki, Tsuneo
• Format: Article
• Language: English
• Subjects: 2-Amino-5-phosphonovalerate - pharmacology; Analysis of Variance; Animals; Behavior, Animal - drug effects; Biological and medical sciences; Cerebral Cortex - drug effects; Cerebral Cortex - physiology; Choice Behavior - drug effects; d, l-2-Amino-5-phosphonopentanoic acid; Discrimination (Psychology) - drug effects; Dose-Response Relationship, Drug; Excitatory Amino Acid Antagonists - pharmacology; Exploratory Behavior - drug effects; Fundamental and applied biological sciences. Psychology; Male; Microinjection; Muscarinic Antagonists - pharmacology; Object recognition; Perirhinal cortex; Rats; Rats, Long-Evans; Receptors, Muscarinic - physiology; Recognition (Psychology) - drug effects; Recognition (Psychology) - physiology; Scopolamine; Scopolamine Hydrobromide - pharmacology; Vertebrates: nervous system and sense organs
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2003.11.049

To determine the possible involvement of N-methyl- d-aspartate (NMDA) and muscarinic activation of the perirhinal cortex in object recognition, an NMDA antagonist ( d, l-2-amino-5-phosphonopentanoic acid (AP5)) and a muscarinic antagonist (scopolamine) were injected into the perirhinal cortex of rats. A high dose of AP5 (60 mM) and two doses of scopolamine (20 and 80 mM), but not a low dose of AP5 (30 mM) alone, significantly impaired discrimination between novel and familiar objects in a spontaneous object recognition task, which is one of the recognition memory tasks. These results suggest that activation of both NMDA and muscarinic receptors in the perirhinal cortex contributes to object recognition.