Biomedical subjects

John M Roll

Publications and source records attributed to John M Roll.

2 recordsLinked to original sources

PubMed2003

Extracellular glutamate decrease in accumbens following cued food delivery.

This study examined the effects of cued vs non-cued food delivery/consumption on extracellular glutamate and dopamine in the nucleus accumbens of food-deprived rats. Animals that always received a food pellet following a series of auditory tones showed a significant decrease in extracellular glutamate following food consumption, whereas animals that had not been previously exposed to tone-food pairing did not (p<0.05). In contrast, extracellular dopamine was significantly increased in the nucleus accumbens during the first time period after food consumption (p<0.05) regardless of whether animals had been exposed to prior tone-food pairing. Results suggest that food delivery/consumption is associated with a decrease in accumbal glutamate if food delivery has been previously paired with predictive environmental cues.

Acoustic Stimulation↗

PubMed2002

Establishment of a diazepam preference in human volunteers following a differential-conditioning history of placebo versus diazepam choice.

This study examined whether preference for a drug (diazepam or placebo) could be switched using conditioning procedures. During the first 4 sessions of Phase 1, 6 participants received 5 mg of diazepam or placebo under double-blind conditions. During the remaining 5 sessions of Phase 1, participants selected the drug they wished to receive. The first 4 sessions of Phase 2 were a replication of Phase 1, except that following ingestion of the drug, participants completed a computer task for which they could earn money. Payment for the computer task was lowest following ingestion of the drug they preferred in Phase I and highest following the drug they had avoided. Preference was reassessed during the last 5 sessions of Phase 2. Five of the participants preferred placebo in Phase 1 but diazepam in Phase 2. Subjective responses to the drugs also changed across the 2 phases.

Adult↗