Dr. Broadbent is a Research
Assistant Professor in the Department of Psychiatry and a
member of the Neuroscience Program. The overall goal of Dr.
Broadbent’s research is to identify behavioral and neuropharmacological
mechanisms that contribute to drug abuse and addiction. Contemporary
theories of addiction propose that a number of processes influence
drug-seeking behavior including genetic differences in sensitivity
to the acute motivational effects of drugs (positive and negative),
behavioral sensitization (increases in the effect of a drug)
following repeated administration, and the development of
conditioned responses to stimuli associated with drug administration.
Three projects are currently being conducted to evaluate the
neural bases and impact of each of these processes on addiction.
Recent findings from one project indicate that genetically
determined differences in the endogenous opioid system may
influence sensitivity to the aversive motivational effects
of alcohol and the amount of alcohol consumed by inbred strains
of mice. Other studies have revealed that GABAB and glutamate
(NMDA) receptors play a significant role in the development
of sensitization to alcohol. A third project is being conducted
to examine the development of Pavlovian conditioned responses
to stimuli paired with drug administration. Expression of
conditioned responses purportedly contributes to drug craving
and relapse to drug use. Additional information regarding
the impact of these conditioned responses on drug-seeking
behavior will be valuable to treatment programs that aim to
decrease drug craving through extinction of conditioned responses.
