Rats received 45 pairings of kindling or sham stimulation in distinctive contexts before a conditioned place preference/aversion test, to determine whether the stimulation and seizures were rewarding or punishing. After more pairings, rats received kindling stimulation in each context (switch test). Ictal measures in this test included afterdischarge duration, clonus duration, latency to clonus...

Recent evidence suggests that rewarding and aversive stimuli affect the same brain areas, including medial prefrontal cortex and nucleus accumbens. Although nucleus accumbens is known to respond to salient stimuli, regardless of their hedonic valence, with selective increased dopamine release, little is known about the role of prefrontal cortex in reward- and aversion-related motivation or abou...

There is a body of evidence implying the involvement of the central glutamatergic system in morphine dependence. In this study, we examined the effect of intracerebroventricular (i.c.v.) administration of a potent glutamate transporter inhibitor, DL-threo-beta-benzyloxyaspartate (DL-TBOA), on acute morphine-induced antinociception, expression of somatic and negative affective components of morp...

The effects of ifenprodil, a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist, on the morphine-induced place preference were examined in mice. Morphine (1-5 mg/kg, s.c.) produced a dose-related place preference in mice. In contrast, ifenprodil alone (5-20 mg/kg, i.p.) did not produce either preference or aversion for the drug-associated place. Pretreatment with ifenprodil (5-20 m...

Peripheral administration of naloxone is known to produce a conditioned place aversion and to block cocaine-induced conditioned place preference. The ventral pallidum receives a dense enkephalinergic projection from the nucleus accumbens and is implicated as a locus mediating the rewarding and reinforcing effects of psychostimulant and opiate drugs. We sought to provide evidence for the involve...

The neurotransmitter, dopamine (DA), has been implicated in place conditioning but the role of D1 and D2 receptors has not been investigated. In Experiment 1, the effects of SKF 38393 (0, 0.01, 0.1, 1.0, 10.0 mg/kg) and quinpirole (0, 0.01, 0.1, 1.0, 2.0, 4.0 mg/kg), preferential D1 and D2 receptor agonists, respectively, were evaluated and compared to (+)-amphetamine (0, 0.01, 0.1, 1.0, 2.0, 4...

In the present study, involvement of the N-methyl-d-aspartate (NMDA) receptors of the CA1 region of dorsal hippocampus (intra-CA1) in the acquisition or expression of morphine-induced conditioned place preference in rats was studied. Male Wistar rats were used in these experiments. NMDA-receptor agonist (NMDA) and antagonist (MK-801) were injected into the CA1 region of the dorsal hippocampus (...