Bryan K Yamamoto
University of Toledo, USA
Title: Interactions between methamphetamine and stress: A dangerous combination
Biography
Biography: Bryan K Yamamoto
Abstract
Substance abuse and stress are typically co-morbid conditions but little is known about how the two combined conditions may affect the neurochemistry of the brain. More specifically, our past and current animal studies have shown that chronic stress augments the acute effects of the widespread drug of abuse, methamphetamine on dopamine and glutamate neurotransmission and also exacerbates the long-term depletions of dopamine and serotonin produced by methamphetamine. We have used a chronic unpredictable stress paradigm that varies the type and time of stress exposures to rats. The advantages of this approach are that the unpredictable nature of the exposures to varied stressors approximates encounters with unexpected stressful life events. Moreover, the paradigm is not confounded with learning and adaptation but chronically elevates plasma corticosterone. Using this model, recent findings will be presented that the serial exposure to chronic unpredictable stress and a binge dosing regimen of methamphetamine also compromises the blood-brain barrier. In addition, animal studies will be described which support the role of corticosterone synthesis and inflammation in mediating the combined effects of chronic stress and methamphetamine on neurotransmitters and blood-brain barrier structure and function. These findings support that importance of considering co-morbid conditions when evaluating and translating the neuropharmacological effects of methamphetamine to human methamphetamine abusers.