Recent anatomical investigations have revealed that the striatum is an intrinsically heterogeneous structure that forms multiple parallel circuits with different cortical areas. The present series of experiments investigated the possibility that such anatomical diversity may promote functional differences between subregions of the rat dorsal striatum. Using different versions of the water maze and radial arm maze tasks, evidence is presented showing that the medial and lateral subregions of the caudate-putamen make distinct contributions to behaviors guided by either ambient spatial or discrete cues. The findings support a multiple subsystems view of dorsal striatal function. Specifically, the lateral (sensorimotor-innervated) caudate-putamen may mediate the process of habit formation based on simple stimulus-response associations, whereas the medial (limbic-innervated) caudate-putamen may contribute to the cognitive/spatial control of behavior in competitive response situations. Further evidence is presented suggesting that the medial caudate-putamen is functionally related to the hippocampal system. Together, these structures may form a functional limbic circuit that mediates the serial processing of cognitive/spatial information.

The present experiments were designed to examine the hypothesis that the hippocampus and caudate nucleus are parts of independent memory systems which differ in the type of memory they mediate. In experiment 1, the mnemonic functions of the hippocampus and caudate were doubly dissociated; lesions of the caudate nucleus impaired acquisition of the "habit memory" component of the 4 x 4 radial maze task, but had no effect the "cognitive memory" component of the task. Lesions of the fimbria-fornix produced the opposite behavioral dissociation. In experiment 2, lesions of the caudate nucleus produced a transient deficit in cognitive win-shift radial maze behavior when rats were allowed to obtain food from maze arms on an unlimited basis prior to win-shift training. In contrast, lesions of the caudate had no effect on win-shift acquisition when rats were allowed to explore an empty maze prior to win-shift training. These results suggest that reinforcement contingencies may be important in determining the type of memory process initiated by a training experience. In experiments 3ab, systemic post-training injection of the dopamine (DA) agonist D-amphetamine (D-AMP) and the DA D2 receptor agonist LY 171555, but not the DA D1 receptor agonist SKF-38393, improved acquisition on both a habit memory win-stay radial maze task, and a cognitive memory win-shift radial maze task. In experiments 4ab, the mnemonic functions of the hippocampus and caudate nucleus were doubly dissociated using post-training intracerebral injections of these same DA agonists. Post-training intracaudate injection of D-AMP, LY 171555, and SKF-38393 improved acquisition of win-stay, but not win-shift radial maze behavior. Post-training intrahippocampal injection of these DA agonists produced the opposite behavioral dissociation. Taken together, the results are consistent with the hypothesis that the caudate nucleus mediates the acquisition of habit memory, while the hippocampus mediates the acquisition

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.

Thesis (M.A.)--Kent State University, 2007. / Title from PDF t.p. (viewed March 27, 2008). Advisor: Chet C. Sherwood. Keywords: hippocampus, spatial memory, diet, habitat, home range, activity pattern, primate, independent contrast. Includes bibliographical references (p. 67-89).

Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on July 13, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Behaviour, Systems and Cognitive Neuroscience, Department of Psychology, University of Alberta." Includes bibliographical references.

Thesis (B.A.)--Haverford College, Dept. of Psychology, 2009. / Includes bibliographical references.

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Neuroscience." Includes bibliographical references (p. 94-112).

Thesis (Ph. D.)--Carleton University, 1995. / Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (M.S.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Michael Babcock. Includes bibliographical references (leaves 43-51).