Neurobiological Basis of Circadian Rhythms
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.
Role of Mast Cells in the Brain
Our project, in collaboration with Dr. Ann-Judith Silverman, concerns the entry of mast cells into the CNS. Mast cells are best known for their role in inflammatory disease. However, they also exist in the CNS and are pluripotent as to the possible secretory products they can release. We have discovered that their numbers in specific brain regions appear to be controlled by developmental age and reproductive status. The goals now are to analyze at a cellular level how they enter the CNS (both physical pathways and potential chemotactic agents) and how they influence the brain vasculature and neuronal transmission (in collaboration with Dr. Lorna Role). We have also begun looking for a functional role of mast cells in the brain. These could include regulating core body temperature after induction of sepsis and also influencing behavior. The implication of mast cells in arousal and behavior like fear and anxiety would be novel evidence for an immune cell's contribution to the neural basis of behavior.