The organophosphate insecticide diazinon and aging: Neurobehavioral and mitochondrial effects in zebrafish exposed as embryos or during aging.

Dr. Di Giulio serves as Director of Duke University's Integrated Toxicology Program and the Superfund Basic Research Center.

Dr. Di Giulio's research is concerned with basic studies of mechanisms of contaminant metabolism, adaptation and toxicity, and with the development of mechanistically-based indices of exposure and toxicity that can be employed in biomonitoring. The long term goals of this research are to bridge the gap between mechanistic toxicological research and the development of useful tools for environmental assessment, and to elucidate linkages between human and ecosystem health. The bulk of Dr. Di Giulio's work employs a comparative approach with aquatic animals, particularly fishes, as models. Of particular concern are mechanisms of oxidative metabolism of aromatic hydrocarbons, mechanisms of free radical production and antioxidant defense, and mechanisms of chemical carcinogenesis, developmental perturbations and adaptations to contaminated environments by fishes.

Dr. Levin is Chief of the Neurobehavioral Research Lab in the Psychiatry Department of Duke University Medical Center. His primary academic appointment is as Professor in the Department of Psychiatry and Behavioral Sciences. He also has secondary appointments in the Department Pharmacology and Cancer Biology, the Department of Psychological and Brain Sciences and the Nicholas School of the Environment at Duke. His primary research effort is to understand basic neural interactions underlying cognitive function and addiction and to apply this knowledge to better understand cognitive dysfunction and addiction disorders and to develop novel therapeutic treatments.

The three main research components of his laboratory are focused on the themes of the basic neurobiology of cognition and addiction, neurobehavioral toxicology and the development of novel therapeutic treatments for cognitive dysfunction and substance abuse. Currently, our principal research focus concerns nicotine. We have documented the basic effects of nicotine on learning memory and attention as well as nicotine self-administration. We are continuing with more mechanistic studies in rat models using selective lesions, local infusions and neurotransmitter interaction studies. We have found that nicotine improves memory performance not only in normal rats, but also in rats with lesions of hippocampal and basal forebrain connections. We are concentrating on alpha7 and alpha4beta2 nicotinic receptor subtypes in the hippocampus, amygdala , thalamus and frontal cortex and how they interact with dopamine D1 and D2 and glutamate NMDA systems with regard to memory and addiction. I am also conducting studies on human cognitive behavior. We have current studies to assess nicotine effects on attention, memory and mental processing speed in schizophrenia, Alzheimer's Disease and Attention Deficit Hyperactivity Disorder. In the area of neurobehavioral toxicology, I have continuing projects to characterize the adverse effects of prenatal and adolescent nicotine exposure. Our primary project in neurobehavioral toxicology focuses on the cognitive deficits caused by the marine toxins. The basic and applied aims of our research complement each other nicely. The findings concerning neural mechanisms underlying cognitive function help direct the behavioral toxicology and therapeutic development studies, while the applied studies provide important functional information concerning the importance of the basic mechanisms under investigation.