Michael Scott Bowers

Learn More
Persistent drug-seeking behavior is hypothesized to co-opt the brain's natural reward-motivational system. Although ventral tegmental area (VTA) dopamine (DA) neurons represent a crucial component of this system, the synaptic adaptations underlying natural rewards and drug-related motivation have not been fully elucidated. Here, we show that(More)
The core and shell of the nucleus accumbens have critical, differential roles in drug-dependent behaviors. Here we show that operant cocaine self-administration inhibits long-term depression (LTD) in both structures after 1 d of abstinence. However, after 21 d of abstinence, LTD was abolished exclusively in the nucleus accumbens core of cocaine(More)
Orexin A/hypocretin-1 (oxA/hcrt-1) is known to be a modulator of dopamine-dependent neuronal activity and behaviors. However, the role of this system in driving motivated behaviors remains poorly understood. Here, we show that orexin/hypocretin receptor-1 (ox/hcrt-1R) signaling is important for motivation for highly salient, positive reinforcement. Blockade(More)
BACKGROUND Continued consumption of alcohol despite deleterious consequences is a hallmark of alcoholism and represents a critical challenge to therapeutic intervention. Previous rat studies showed that enduring alcohol self-administration despite pairing alcohol with normally aversive stimuli was only observed after very long-term intake (>8 months).(More)
Experience-dependent plasticity at excitatory synapses of the mesocorticolimbic system is a fundamental brain mechanism that enables adaptation to an ever-changing environment. These synaptic responses are critical for the planning and execution of adaptive behaviors that maximize survival. The mesocorticolimbic system mediates procurement of positive(More)
Using sensory information for the prediction of future events is essential for survival. Midbrain dopamine neurons are activated by environmental cues that predict rewards, but the cellular mechanisms that underlie this phenomenon remain elusive. We used in vivo voltammetry and in vitro patch-clamp electrophysiology to show that both dopamine release to(More)
The Scheduled High Alcohol Consumption (SHAC) binge drinking model is a simple, partial murine model with which to investigate some of the neurobiological underpinnings of alcoholism. The SHAC model was used to characterize monoamine and amino acid adaptations produced in the nucleus accumbens (NAC) by repeated bouts of high alcohol consumption. In vivo(More)
Changing the activity of ventral tegmental area (VTA) dopamine neurons from pacemaker to burst firing is hypothesized to increase the salience of stimuli, such as an unexpected reward, and likely contributes to withdrawal-associated drug-seeking behavior. Accordingly, pharmacological, behavioral, and electrophysiological data suggest an important role of(More)
Approximately 90% of alcoholics relapse within 4 years, in part because of an enhanced motivation to seek alcohol (EtOH). A novel G protein modulator (Gpsm1/AGS3) was up-regulated in the rat nucleus accumbens core (NAcore) but not in other limbic nuclei during abstinence from operant EtOH self-administration. Furthermore, NAcore AGS3 knockdown reduced EtOH(More)
The cellular mechanisms underlying pathological alcohol seeking remain poorly understood. Here, we show an enhancement of nucleus accumbens (NAcb) core action potential firing ex vivo after protracted abstinence from alcohol but not sucrose self-administration. Increased firing is associated with reduced small-conductance calcium-activated potassium channel(More)