Neurobiology of Learning and Memory 76, 106–116 (2001) doi:10.1006/nlme.2000.3989, available online at http://www.idealibrary.com on Role of the Medial and Lateral Caudate-Putamen in Mediating an Auditory Conditional Response Association Spencer Adams, Raymond P. Kesner, and Michael E. Ragozzino Department of Psychology, University of Utah, 380 South 1530 East, Room 502, Salt Lake City, Utah 84112-0251 Published online March 21, 2001 Rats with quinolinic acid lesions of the medial or lateral caudate-putamen (CPu) and controls were tested for performance of a previously learned auditory conditional response association task. The task involved the selection of two possible responses when presented with one of two different tones. Results indicated that lesions of either the medial or the lateral CPu produced a sustained deficit in the auditory conditional response association task. Only the lateral CPu lesioned rats exhibited transient motor problems immediately following surgery, but these problems did not interfere with the execution of the appropriate responses. It is suggested that both the medial and the lateral CPu are involved in response selection and response separation within egocentric space.  2001 Academic Press INTRODUCTION It has been suggested that one of the major functions of the caudate-putamen (CPu) in rats is to support sensory–motor integration, including learning of stimulus–response associations usually defined by tasks in which a particular motor response is reinforced in the presence of a single cue or tasks that require a consistent choice of direction or consistent choice to initiate or withhold responding (Phillips & Carr, 1987; McDonald & White, 1993). Support for this idea comes from a large number of studies indicating that damage to the dorsal CPu impairs conditional visual discrimination (Reading, Dunnett, & Robbins, 1991; Winocur & Eskes, 1998), right/left maze discrimination (Cook & Kesner, 1988), runway learning (Kirkby, Polgar, & Coyle, 1981), eight-arm maze learning (refer- ence memory or nonvarying component of the task) (Colombo, Davis, & Volpe, 1989; Packard & White,1990) and cued eight-arm radial arm maze and cued Morris water maze learning (Packard & White, 1990; Whishaw, Mittleman, Bunch, & Dunnett, 1987). This research was supported by NIH Grant 2RO1NS20771-13 and NSF Grant BNS 892-1532. Address correspondence and reprint requests to Raymond P. Kesner, University of Utah, Department of Psychology, 380 South 1530 East, Room 502, Salt Lake City, UT 84112-0251. Fax: (801) 581-5841. E-mail: rpkesner@behsci.utah.edu. 1074-7427/01 $35.00 106 Copyright  2001 by Academic Press All rights of reproduction in any form reserved.