Interests: Neuroendocrinology and medical neuroscience. Specialty areas: neural control of hydromineral balance, autoregulation of magnocellular neuroendocrine cells by vasopressin and actions of endocrine disruptors; mechanisms underlying excitotoxicity and neuroprotection in neurotrauma and stroke injury models.

One main focus of our research is autocontrol of neuroendocrine cells of the supraoptic nucleus of the rat hypothalamus (SON) which produce vasopressin (VP) and oxytocin (OXY), hormones involved in osmoregulation, lactation and parturition as well as cardiovascular function. A recent finding from our lab, modulation of stimulated glutamate release by VP and OXY, suggests that locally released OXY and VP may autoregulate SON activity, in part, by modulating the release of excitatory amino acids from afferent terminals targeting these cells. We are investigating the physiological significance of dendritic signaling by VP and the mechanisms underlying dendritic release of VP including the actions of nitric oxide, VP autoreceptors, pituitary adenylate cyclase activating peptide (PACAP) and glutamate receptors. We have recently discovered a novel role of intra-SON PACAP in controlling VP release stimulated by osmotic activation. Studies are underway that examine the receptor subtypes and signal transduction processes involved in PACAP control over VP release. Other projects examine the mechanisms underlying disruption of osmoregulation and other neuroendocrine processes by the environmental toxins, persistent organic pollutants such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs).

Other studies aim to identify neuroprotective mechanisms relevant to SON viability (these cells are less susceptible to excitotoxic injury (in vitro) and ischemic neuronal death (in vivo) relative to cortical and other central neurons. Our lab has shown that resistance to glutamate-evoked excitotoxicity may be associated with a greater capacity for glutamate clearance and more efficient calcium extrusion and free radical scavenging. In collaboration with investigators at Loma Linda University we have been using brain imaging to describe evolution of brain damage and to predict outcome. More recently, we have been using stem cells to alleviate adverse effects of neurotrauma and other injuries. Our findings may lead eventually to the development of alternative therapies for stroke and neurodegenerative diseases.