Glutamate dynamics in the dorsolateral striatum of rats with goal-directed and habitual cocaine-seeking behavior.

The shift from drug abuse to addiction is considered to arise from the transition between goal-directed and habitual control over drug behavior. Habitual responding for appetitive and skill-based behaviors is mediated by potentiated glutamate signaling in the dorsolateral striatum (DLS), but the state of the DLS glutamate system in the context of habitual drug-behavior remains undefined. Evidence from the nucleus accumbens of cocaine-experienced rats suggests that decreased transporter-mediated glutamate clearance and enhanced synaptic glutamate release contribute to the potentiated glutamate signaling that underlies the enduring vulnerability to relapse.

Characterization of striatum-mediated behavior and neurochemistry in the DJ-1 knock-out rat model of Parkinson's disease.

The recently developed DJ-1 knockout (KO) rat models the DJ-1 (or PARK7) loss-of-function mutation responsible for one form of early-onset familial Parkinson's disease (PD). Prior studies demonstrate that DJ-1 KO rats present progressive dopamine (DA) cell body degeneration in the substantia nigra pars compacta between 4 and 8 months of age. Furthermore, as some motor deficits emerge before the significant loss of DA cells, this mutation may yield a period of DA neuron dysfunction preceding cell death that may also contribute to cognitive impairments in early PD.

Reward, salience, and attentional networks are activated by religious experience in devout Mormons.

High-level cognitive and emotional experience arises from brain activity, but the specific brain substrates for religious and spiritual euphoria remain unclear. We demonstrate using functional magnetic resonance imaging scans in 19 devout Mormons that a recognizable feeling central to their devotional practice was reproducibly associated with activation in nucleus accumbens, ventromedial prefrontal cortex, and frontal attentional regions. Nucleus accumbens activation preceded peak spiritual feelings by 1-3 s and was replicated in four separate tasks.