This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Tsukahara, S. Articles by Yamanouchi, K. Search for Related Content PubMed PubMed Citation Articles by Tsukahara, S. Articles by Yamanouchi, K.

Sex Difference in Septal Neurons Projecting Axons to Midbrain Central Gray in Rats: A Combined Double Retrograde Tracing and ER-Immunohistochemical Study

Advanced Research Center for Human Sciences (S.T., K.Y.) and Department of Basic Human Sciences (K.Y.), Laboratory of Neuroendocrinology, School of Human Sciences, Waseda University, Mikajima, Tokorozawa, Saitama 359-1192, Japan

Address all correspondence and requests for reprints to: Korehito Yamanouchi, Laboratory of Neuroendocrinology, Department of Basic Human Sciences, School of Human Sciences, Waseda University, 2-579-15, Mikajima, Tokorozawa, Saitama 359-1192, Japan.

Sex difference in the number of neurons projecting axons from the lateral septum (LS) to the midbrain central gray (MCG) that are concerned with the lordosis-inhibiting system was investigated by injection of Fluoro-Gold (FG), a retrograde tracer, into the rostral MCG on the right side in male and female rats. Immunohistochemistry for ER- and -ß was also performed with or without combination with FG immunostaining. All animals were gonadectomized. Lordosis was observed after treatment with E2 in some animals. In the results, lordosis was rare in males, compared with females. FG-immunoreactive (ir) cells were concentrated in the intermediate LS on the right side, and its number in the females was significantly higher than that in the males. There was no sex difference in the distribution and number of ER-ir and ERß-ir cells in the LS. Furthermore, the number of ERs-ir cells was not influenced by E2 in either males or females. Double FG-ERß-ir cells were less than 20% of total FG-ir cells in the LS in both males and females. These data suggest that the LS-MCG connection is sexually dimorphic but that there is no sex difference in the expression of ERs in the LS.