RECOGNITION MEMORY IN RATS - II - NEUROANATOMICAL SUBSTRATES

A discussion of the neuroanatomical systems thought to be of importanc e for the mediation of recognition memory in the rat warrants consider ation of different, but not necessarily exclusive concepts. An importa nt concept is the hypothesis that a dichotomy in the neural systems me diating spatial and non-spatial (item) memory exists in the rat. We ha ve adopted a model of recognition memory suggesting that information a bout previously encountered items is stored in a dynamic pattern of ne ural activity and not in a localized representation, These patterns ar e features of distributed neuronal networks and different networks may process different forms of recognition memory. Two parallel-distribut ed neuronal networks are proposed in the rat. Network 1 is essential f or the processing of non-spatial/item recognition memory processes and incorporates the cortical association areas such as TE1, TE2 and TE3, the rhinal cortices, the mediodorsal thalamic nucleus and prefrontal cortical areas. Network 2 comprises the hippocampus, mamillary bodies, anterior thalamic nuclei and medial prefrontal areas, especially the prelimbic cortex, and is suggested to, be pivotal for the processing o f spatial recognition memory. (C) 1998 Elsevier Science Ltd. All right s reserved.