ProfessorDirector, Animal Behavior Core FacilityDivision of Neurobiology and Behavioral ResearchDepartment of Psychiatry and Human BehaviorOffice: G111 and TR319(601) 984-6684; Fax: (601) 984-5899Email
My research focuses upon uncovering the basic mechanisms underlying the proposed developmental function of rapid eye-movement (REM) sleep in brain maturation. Our early work on cats and rats in this area has provided a major portion of the available data that supports this so called “ontogenetic hypothesis”, which posits a role for REM sleep in cortical development. Research in my laboratory also has provided the first data demonstrating that REM sleep deprivation during an early critical period directly affects plasticity mechanisms involved in developing synaptic connectivity in the maturing brain. Our work in both visual cortex and hippocampus has begun to uncover some of the electrophysiological and molecular mechanisms that contribute to the effects this sleep state has on developmental synaptic plasticity. My laboratory has also developed novel, computer controlled methods for automatically manipulating REM sleep that is not subject to many of the critiques of the typically used ‘flower pot’ techniques of REM sleep deprivation, while being just as effective in reducing REM sleep but without disturbing slow wave sleep amounts. In addition, my studies have explored sleep and its mechanisms in several species, including birds, rodents, and cats as well as ferrets.
Ongoing research projects include studies on the relatively long-term effects of neonatal REM sleep disturbances on brain maturation at the behavioral, electrophysiological and molecular basis. Early work on this model had demonstrated the effects of neonatal REM sleep disturbance on in vitro hippocampal synaptic plasticity could last for at least a week past the final REM sleep disturbance. Since then we have extended these initial studies to show that neonatal REM sleep disturbance affects in vitro electrophysiology and synaptic plasticity for nearly a month after that, a time when the animal is nearly an adult. In addition, these older animals show gene and protein changes that are different from control animals. More recently we have gone on to demonstrate that there are additional effects of neonatal REM sleep disturbance on behavior measures relating to socialization, memory and learning at the later developmental time point as well.
Presently, I also collaborate with a number of NIH-funded researchers at UMMC that are conducting sleep studies in my sleep research facilities under my purview as Director of the Center for Psychiatric Neuroscience, Animal Behavior Core (ABC).