Our research is focused upon the integrative neurobiology of two systems in the brain: (1) the reproductive neuroendocrine system, which is
comprised of gonadotropin-releasing hormone (GnRH) neurons that are critical for the control of the hypothalamic-pituitary-gonadal axis;
and (2) the circadian timing system, which includes an endogenous biological clock in the suprachiasmatic nucleus (SCN) of the hypothalamus that
plays a key role in regulating daily rhythms in behavior and physiology. For studies of the reproductive neuroendocrine system, ongoing projects
include neuroanatomical studies of the circuitry responsible for the estrous/menstrual cycle, and for expression of seasonal rhythms of reproduction. In our studies of circadian clocks, we are currently interested in the mechanisms by which neurons in the SCN and other forebrain regions regulate diurnal rhythms in motivation and reward. We use a variety of approaches, ranging from molecular to behavioral, to understand the functional anatomical circuitry underlying these fundamental aspects of physiology and behavior.
• Smith, J.T., Coolen, L.M., Kriegsfeld, L.J., Sari, I.P., Jaafarzadehshirazi, M.R., Maltby, M., Bateman, K., Goodman, R.L., Tilbrook, A.J., Ubuka, T., Bentley, G.E., Clarke, I.J. and Lehman, M.N. (2008) Variation in kisspeptin and gonadotropin-inhibitory hormone expression and terminal connections to GnRH neurons in the brain: a novel medium for seasonal breeding in the sheep. Endocrinology Jul 10 [Epub ahead of print]
• Bogusz, A.L., Hardy, S.L., Lehman, M.N., Connors, J.M., Hileman, S.M., Sliwowska, J.H., Billings, H.J., McManus, C.J., Valent, M., Singh, S.R., Coolen, L.M. and Goodman R.L. (2008) Evidence that gamma-amino butyric acid is part of the neural circuit mediating estradiol negative feedback in anestrous ewes. Endocrinology 149(6): 2762-2772.
• Goodman, R.L., Lehman, M.N. , Smith, J.T., Coolen, L.M., de Oliveira, C.V.R., Jafarzadehshirazzi, M.R., Periera, A., Iqbal, J., Caraty, A., Ciofi, P. and Clarke, I.J. (2007) Kisspeptin cells in the arcuate nucleus of the ewe express both dynorphin A and neurokinin B. Endocrinology 148(12): 5752-5720.
• Foradori, C.D., Handa, R.J., Amstalden, M., Coolen, L.M., Singh, S.R., McManus, C.J., Goodman, R.L. and Lehman, M.N. (2007) Orphanin FQ: Evidence for a central role in control of the reproductive neuroendocrine system. Endocrinology 148(10): 4993-5001.
• Adams, V.L., Goodman, R.L., Salm, A., Coolen, L.M., Karsch, F.J. and Lehman, M. N. (2006). Morphological plasticity in the neural circuitry responsible for seasonal breeding in the ewe. Endocrinology 147(10): 4843-4851.
• Sliwowska , J.H., Billings, H.J., Goodman, R.L. and Lehman, M. N. (2006) . Immunocytochemical colocalization of GABA-B receptor subunits in gonadotropin releasing hormone (GnRH) neurons of the sheep. Neuroscience 141(1): 311-319.
• Guo, H., Brewer, J.M., Lehman, M. N., and Bittman, E. L. (2006). Suprachiasmatic regulation of circadian rhythms of gene expression in hamster peripheral organs: effects of transplanting the pacemaker. J. Neuroscience 26(24): 6406-12.