In addition to its primary function as a reproductive hormone, the ovarian hormone estrogen affects performance on various measures of learning and memory in mammals. Although the mechanisms underlying these effects are as yet unclear, estrogen affects the structure and function of the hippocampus, an area of the brain involved in learning and memory. The primary goal of the current project is to understand the mechanisms by which estrogen exerts its effects in the hippocampus and on associated behaviors. Experiments in this project will investigate the role of acetylcholine, a neurotransmitter whose activity is modulated by estrogen, in the ability of estrogen to effect change in the rat hippocampus. Results of these experiments will determine the role of a subtype of acetylcholine receptor, the M2 muscarinic receptor, in the ability of estrogen to affect the hippocampus and to affect performance on tasks of learning and memory. Experiments will also investigate the effects of different regimens of estrogen replacement, previously shown to differentially affect the activity of acetylcholine, on the hippocampus and on tasks of learning and memory. The results of the experiments in this project should contribute to the understanding of how estrogen acts in the brain to affect cognitive functioning. In addition, the activities in this project will provide increased research opportunities for undergraduate and graduate students at the University of New Orleans. The University of New Orleans is an urban campus with a high percentage of minority and female student enrollment and with a student body that consists primarily of residents from the state of Louisiana, a geographical region that has traditionally been underrepresented in the sciences. Thus, the participation of students at the University of New Orleans in the proposed experiments will broaden participation of underrepresented groups in scientific endeavors.
