Bruce Nock, PhD
Associate Professor of Neurobiology in Psychiatry
Areas of Research Interests
Paternal exposure to certain exogenous agents, e.g., chemotherapeutics, carcinogens, mutagens, environmental toxins or recreational drugs, can adversely affect offspring viability, development and function. Morphine, the focus of our current studies, was one of the first drugs shown to have paternal-mediated consequences for offspring. They include physiological, endocrine and cognitive deficits and an altered pharmacological response to opioids. Pregnancy outcome and offspring viability are also adversely affected by paternal morphine exposure. Paternal exposure to other opioids, including methadone, levorphan and dextrorphan, have also been reported to cause deficits in offspring.
In our studies with rats, the developmental stage, morphine dose and interval between morphine exposure and breeding influenced outcome. A single morphine injection 24 hours before mating with a drug-naive female was sufficient to reduce litter size, markedly increase neonatal mortality and enhance adult offspring sensitivity to analgesic effects of morphine. We also observed adverse effects of paternal morphine exposure on preimplantation processes, litter sizes, and hypothalmic-pituitary-adrenocortical and hypothalmic-pituitary-gonadal hormone levels in adult offspring using other treatment paradigms.
Our current research continues our studies of the effects of paternal morphine exposure. It focuses on gender-specific endocrine deficits we previously observed in adult offspring of fathers chronically treated with morphine during adolescence. Our general goal is to more clearly define the nature and consequences of these deficits.
Nock B, Wich M, Cicero TJ: Chronic exposure to morphine increases corticosteroid-binding globulin. J Pharmacol Exp Ther 1997; 282:1262-1268.
Nock B, Cicero TJ, Wich M: Chronic exposure to morphine decreases physiologically active corticosterone in both male and female rats but by different mechanisms. J Pharmacol Exp Ther 1998; 286:875-882.
Nock, B, Wich, M, Cicero, TJ, OConnor, LH: Testosterone is required for corticosteroid-binding globulin upregulation by morphine to be fully manifested. Pharmacol Biochem Behav 2000; 67:193-198.
Hampson BA, Zabek, MA, Pollitt, CC, Nock, B: Health and Behaviour Consequences of Feral Horse Relocation. The Rangeland J. 2011, 33:173–180.