Rae Silver, Ph.D.Kaplan Professor, Psychology
Area of Research
Identification and functional analysis of the mammalian biological clock
All organisms have internal biological clocks which serve to recognize local time of day and to temporally organize behavioral and physiological functions. Circadian rhythms continue to oscillate within an approximate 24 hour period in the absence of external cues, although ordinarily these rhythms are synchronized to the day-night cycle. The functional components of the "biological clock" include an input pathway that synchronizes to the environment, a pacemaker that generates the oscillation, and output pathways that control overt rhythms. The circadian system has marked implications for shift work and jet lag. Research in the lab uses neural tissue transplants and a variety of anatomical techniques to study this system.
BEHAVIORALLY TRIGGERED APPEARANCE OF MAST CELLS INTO THE BRAIN
We have discovered that sexual behavior triggers the appearance of mast cells in the brain of doves, and that sex steroids activate brain mast cells, causing them to release their contents. This is a new mode of communication between the immune, neural and endocrine systems. These immunocytes, serving as mobile single cell glands, are likely to be a phylogenetically ancient system that rapidly delivers otherwise unavailable biologically active materials to specific brain regions upon demand. Currently, we are working on understanding the function of brain mast cells in avian and mammalian species.
Wilhelm M, King B, Silverman AJ, Silver R. (2000) Gonadal steroidsregulate the number and activational state of mast cells in the medialhabenula. Endocrinology. 141:1178-86.
Silverman AJ, Sutherland AK, Wilhelm M, Silver R. (2000) Mast cells migrate from blood to brain. J Neurosci. 20:401-8.
LeSauter J, Silver R. (1999) Localization of a suprachiasmatic nucleus subregion regulating locomotor rhythmicity. J Neurosci. 19:5574-85.
Silver R, LeSauter J, Tresco PA, Lehman MN. (1996) A diffusible coupling signal from the transplanted suprachiasmatic nucleus controlling circadian locomotor rhythms. Nature. 382:810-3.