|Eric L. Bittman
Professor of Biology, University of Massachusetts
Ph.D.: University of California at Berkeley
Circadian Rhythms, Reproduction, and Seasonal Changes in Brain Function
My laboratory studies the molecular and neural basis of endogenous daily (circadian) rhythms in mammals. We study the suprachiasmatic nucleus of the hypothalamus (SCN), a pacemaker critical not only to activity rhythms but also to estrous cycles, hormonal rhythms, and seasonal breeding. The SCN controls secretion of the pineal gland hormone melatonin, whose duration is detected using highly specific cell membrane receptors in the brain.
We are characterizing specific SCN cell types which generate circadian oscillations, ensure their synchronization with the outside world, and communicate with the rest of the brain.
The appropriate timing of ovulation is controlled by both signals from the ovary and the circadian clock. Projections of the SCN contact not only neurons which contain estrogen receptors, but also those which regulate the pituitary. Furthermore, estrogen-responsive cells reciprocate to regulate circadian rhythms through their projections to the SCN.
What seasonal changes in brain function drive fluctuations in reproduction, sexual behavior, and energy metabolism? We find that daylength regulates the incorporation of neurons born in adulthood.
We are discovering mechanisms by which the nervous system integrates environmental (photoperiodic) information with internal (hormonal) messages in order to adapt to season.
Representative publications: (Click on (MEDLINE) to view Medline abstracts.)
Tetel M.J., Ungar, T.C., Hassan, B., and Bittman, E.L. 2004. Photoperiodic regulation of androgen receptor and steroid receptor coactivator-1 in Siberian hamster brain. Molecular Brain Research , in press.
Tong, Y, Guo, H., Brewer, J.M., Lee, H, Lehman, M.N., and Bittman, E.L. 2004. Oscillating expression of haPer1 and haBmal1 in peripheral organs of Syrian hamsters. J. Biol. Rhythms . 19: 113-125.
Bittman, E.L. , Doherty, L., Huang L., and Paroskie, A. 2003. Period gene expression in mouse endocrine tissues. Am. J. Physiol. Regul. Integr. Comp. Physiol. 285: R561-569.
Bittman, E.,L. , Ehrlich, D.A., Ogdahl, J.L., and Jetton, A.E. 2003. Photoperiod and testosterone regulate androgen receptor immunostaining in the Siberian hamster brain. Biol. Reprod. 69: 876-884.
Huang, L., and Bittman, E.L. 2002. Olfactory bulb cells generated in adult male golden hamsters are specifically activated by exposure to estrous females. Hormones and Behavior , 41: 343-50.
Fukuhara, C., J. M. Brewer, J. C. Dirden, E. L. Bittman, G. Tosini and M. E. Harrington (2001). "Neuropeptide Y rapidly reduces Period 1 and Period 2 mRNA levels in the hamster suprachiasmatic nucleus." Neurosci Lett 314(3): 119-22.
Song, C.K., Bartness, T.J., Petersen, S.L., and Bittman, E.L. (2000). Co-expression of melatonin (MEL1a) receptor and arginine vasopressin mRNAs in the Siberian hamster suprachiasmatic nucleus. J. Neuroendocrinol., 12:627-634. MEDLINE
de la Iglesia, H.O., Blaustein, J.D., and Bittman, E.L. (1999). Estrogen receptor-immunoreactive neurons project to the suprachiasmatic nucleus of the female Syrian hamster. J. Neuroendocrinol 11:481-490. MEDLINE
Meyer-Bernstein, E.L., Jetton, A.E., Matsumoto, S.-I., Markuns, J.F., Lehman, M.N., and Bittman, E.L. (1999). Effects of suprachiasmatic transplants on circadian rhythms of neuroendocrine function in golden hamsters. Endocrinol 140:207-218. (MEDLINE)
Bittman, E.L., Tubbiola, M.L., Foltz, G., and Hegarty, C.M. (1999). Effects of photoperiod and androgen on pro-opiomelanocortin gene expression in the arcuate nucleus of golden hamsters. Endocrinol 140:197-206. (MEDLINE)
Vernadakis, A.J, Bemis, W.E., and Bittman, E.L. (1998). Localization and partial characterization of melatonin receptors in amphioxus, hagfish, lamprey and skate. Gen Comp Endocrinol 110:67-78. (MEDLINE)
Huang, L., DeVries, G.J., and Bittman, E.L. (1998). Photoperiod regulates neuronal bromodeoxyuridine labeling in the brain of a seasonally breeding mammal. J. Neurobiol 36:410-420 . (MEDLINE)
Powers, J.B., Jetton, A.E., Mangels, R.A., and Bittman, E.L. (1997). Effects of photoperiod duration and melatonin signal characteristics on the reproductive systems of male Syrian hamsters. J. Neuroendocrinol 9:451-466. (MEDLINE)
Matsumoto, S., Basil, J., Jetton, A., Lehman, M.N., and Bittman, E.L.(1996). Control of phase and period of circadian rhythms restored by suprachiasmatic grafts. J. Biol Rhythms11:145-162.9 (MEDLINE)
Bittman EL (1978) Hamster Refractoriness: The role of insensitivity of pineal target tissues. Science 202: 648-650.
Bittman EL, Goldman BD, Zucker I (1979) Testicular responses to melatonin are altered by lesions of the suprachiasmatic nuclei in golden hamsters. Biol Reprod 21: 647-656.
Bittman EL, Karsch FJ, Hopkins JW (1983) Role of the pineal gland in ovine photoperiodism: regulation of seasonal breeding and negative feedback effects of estradiol upon LH secretion. Endocrinol 113: 329-336.
Bittman EL, Dempsey RJ, Karsch FJ (1983) Pineal melatonin secretion drives the reproductive response to daylength in the ewe. Endocrinol 113: 2276-2283.
Bittman EL (1986) The role of rhythms in the response to melatonin. In: Photoperiodism Melatonin and the Pineal, Ciba Foundation Symposium #117, Pitman, London, pp. 149-169.
Bittman EL, Karsch FJ (1984) Nightly duration of pineal melatonin secretion determines the reproductive response to inhibitory day length in the ewe. Biol Reproduction 30: 585-593.
Lehman MN, Silver R, Gladstone WR, Kahn R, Gibson M, Bittman EL (1987) Circadian rhythms restored by neural transplant: integration between the graft and the host brain. J Neurosci 7: 1626-1638.
Bittman EL, Lehman MN (1987) Paraventricular neurons control hamster photoperiodism by a predominantly uncrossed descending pathway. Brain Res Bull 19: 687-694.
Bittman EL, Krey LC (1988) Influence of daylength on nuclear androgen receptor occupancy in neuroendocrine tissues of the golden hamster. Neuroendocrinol 47: 61-67.
Bittman EL, Crandell RG, Lehman MN (1988) Influences of the paraventricular and suprachiasmatic nuclei and olfactory bulbs on melatonin responses in the golden hamster. Biol Reprod 40: 118-126.
Krey LC, Ronchi E, Bittman EL (1989) Effects of daylength on androgen metabolism and on pulsatile luteinizing hormone secretion in male golden hamsters. Neuroendocrinology 50: 533-542.
Bittman EL, Blaustein JD (1990) Effects of day length on sheep neuroendocrine estrogen and progestin receptors. Am J Physiol 258: R135-R142.
Bittman EL, Hegarty CM, Layden MQ, Jonassen JA (1990) Photoperiodic regulation of steroid receptors, sexual behavior, pituitary mRNA in female golden hamsters. J Mol Endocrinol 5: 15-25.
Bittman EL, Weaver DR (1990) Distribution of melatonin receptors in neuroendocrine tissues of the ewe. Biol Reprod 43: 986-993.
Bittman EL, Bartness TJ, Goldman BD, De Vries GJ, (1991) Suprachiasmatic and paraventricular control of photoperiodism in siberian hamsters. Am J Physiol 260: R90-101.
Bartness TJ, Goldman BD, Bittman EL (1991) Suprachiasmatic lesions block responses to melatonin in siberian hamsters. Am J Physiol 260: R102-112.
Lehman MN, Silver R, Bittman EL (1991) Anatomy of suprachiasmatic nucleus grafts. In: Suprachiasmatic Nucleus:The Mind's Clock, Klein DC, Moore RY, Reppert SM eds., Oxford University Press, NY, pp. 349-374.
Bittman EL, Jonassen JA, Hegarty CM (1992) Influences of photoperiod and estradiol on pulsatile LH secretion and adenohypophyseal gene expression in ovariectomized golden hamsters. Biol Reprod 47: 66-71.
Bittman EL (1992) Melatonin: a durational signal regulating steroid-dependent and independent aspects of limbic and hypophyseal function. In: Melatonin and the Pineal Gland: From Basic Science to Clinical Application, Touitou Y, ed., Excerpta Medica, Amsterdam, pp. 151-158.
Bittman EL (1993) The sites and consequences of melatonin binding in mammals. Amer Zool 33: 200-211.
Bittman EL (1993) Melatonin binding sites. In: Receptors: Model Systems and Specific Receptors. Methods in Neurosciences, Conn PM ed., Volume 11, Academic Press, NY pp. 105-121.
Bartness TJ, Goldman BD, Hastings MH, Powers JB, Bittman EL (1993) The timed-infusion paradigm: what has it taught us about melatonin action? J Pineal Res 15: 161-190.
Tubbiola, M.L., and Tubbiola, M.L., and Bittman, E.L. (1994) Steroidal and photoperiodic regulation of opiate binding in male golden hamsters. J Neuroendocrinol 6:317-322.
Bittman, E.L., Thomas, E.M., and Zucker, I. (1994). Melatonin binding sites in sciurid and hystricomorph rodents: studies on ground squirrels and guinea
Tubbiola, M.L., and Bittman, E.L. (1995). Short days increase sensitivity to methadone inhibition of male copulatory behavior. Physiol Behav 58:647-651.
de la Iglesia, H.O., Blaustein, J.D., and Bittman, E.L. (1995). The suprachiasmatic area in the female hamster projects to neurons containing estrogen
Maywood E.S., Bittman, E.L., Ebling, F.J.P., Barrett, P., Morgan, P., and Hastings, M.H. (1995). Regional distribution of iodomelatonin binding sites
Maywood, E.S., Bittman, E.L., and Hastings, M.H. (1996). Lesions of the melatonin- and androgen-responsive tissues of the dorsomedial nucleus of the hypothalamus block the gonadal response of male Syrian hamsters to programmed infusions of melatonin. Biol. Reprod. 54:470-477.
Bittman, E.L., Jetton, A.E., Villalba, C., and De Vries, G.J. (1996). Effects of photoperiod and androgen on pituitary function and neuropeptide staining in Siberian hamsters. Amer. J. Physiol. 271:R64-72. (MEDLINE)