UC Berkeley Biological Clocks Laboratory
The Zucker Laboratory

Lab Overview
    Our work has long been concerned with biological rhythms. Originally (1969-on) the focus was on circadian rhythms; beginning in 1974 and presently, the emphasis is on annual rhythms. Among the ~15 different mammalian species studied were golden-mantled and flying squirrels, several species of Peromyscus, several vole species (Microtus), pallid bats and three hamster species.

    We are concerned with the neuroendocrine substrates that mediate annual rhythms in reproduction, with emphasis on the role of the pineal hormone melatonin. Behavioral and physiological endpoints monitored, include but are not limited to sex behavior, food intake, body mass, daily torpor, olfactory preferences, hibernation, huddling, plasma concentrations of the hormones LH, FSH, melatonin, androgens and estrogens.

    At present our laboratory houses colonies of Siberian, Syrian and Turkish hamsters and meadow voles. Projects currently in progress include assessment of the role of the dorsomedial nucleus of the hypothalamus as a critical target tissue for mediation of seasonal rhythms in behavior, the mechanisms by which pregnant females communicate day length information to their fetuses, seasonal variation in timing of sex differentiation, the ways in which fur influences energetics and behavior during lactation, and the significance of ultradian rhythms of hormone secretion for maintenance of male sexual behavior and structure. We are about to begin investigation of the significance of the brain peptide oxytocin as mediator of seasonal variations in social behavior of meadow voles. We maintain collaborative arrangements with other laboratories on campus and elsewhere. Such projects presently involve studies of perinatal influences of melatonin on immune function in adulthood, brain temperature control by day length, and the role of a novel brain peptide in initiation of puberty.
 
Irving Zucker | Department of Psychology | 3129 Tolman Hall
University of California | Berkeley, Ca 94720-1650
Phone 510-642-7136 | Fax 510-642-5293

Page Last Modified 11/01/05