Contingent and non-contingent effects of heroin on mu-opioid receptor-containing ventral tegmental area GABA neurons.

Opiate activation of mu-opioid receptors (muORs) in the ventral tegmental area (VTA) modulates gamma-aminobutyric acid (GABA) neurotransmission within the mesocorticolimbic dopamine (DA) reward system. We combined in vivo extracellular electrophysiological recordings in anesthetized and freely behaving rats with intracellular Neurobiotin filling and immunocytochemistry to characterize the effects of opiates on VTA GABA neurons, evaluate their discharge activity during opiate self-administration, and identify the cellular sites for opiate activation. We identified a subpopulation of VTA GABA neurons that was characterized by location, spike discharge profile, activation by microelectrophoretic DA, and response to internal capsule (IC) stimulation.

A novel electroencephalographic analysis method discriminates alcohol effects from those of other sedative/hypnotics.

Here we describe a mathematical and statistical signal processing strategy termed event resolution imaging (ERI). Our principal objective was to determine if the acute intoxicating effects of ethanol on spontaneous EEG activity could be discriminated from those of other sedative/hypnotics. We employed ERI to combine and integrate standard analysis methods to learn multiple signal features of time-varying EEG signals.