Body reactions during chain saw work were studied in 14 subjects. The subjects divided into three groups (control, sulpiride, and propranolol) successively cut down logs with a chain saw for seven minutes. The start of the sawing led to a pronounced increase in heart rate which persisted during the sawing. The groups taking sulpiride and propranolol showed a smaller increase in heart rate compa...

The role of dopamine (DA) in rewarding motivated actions is well established but its role in learning how to avoid aversive events is still controversial. Here we tested the role of D2-like DA receptors in the nucleus accumbens (NAc) and the dorsolateral striatum (DLS) of rats in the learning and performance of conditioned avoidance responses (CAR). Adult male Wistar rats received systemic, int...

Recent work has implicated stimulatory kisspeptin neurons in the arcuate nucleus (ARC) as important for seasonal changes in reproductive function in sheep, but earlier studies support a role for inhibitory A15 dopaminergic (DA) neurons in the suppression of GnRH (and LH) pulse frequency in the nonbreeding (anestrous) season. Because A15 neurons project to the ARC, we performed three experiments...

Temporal changes in the avoidance responses and serum prolactin levels were investigated for a 360 min period after s.c. administration of antipsychotic drugs such as chlorpromazine (2 mg/kg), prochlorperazine (2 mg/kg), haloperidol (0.035 mg/kg), droperidol (0.03 mg/kg), YM-09151-2 (0.005 mg/kg) and sulpiride (80 mg/kg) in rats. Male adult rats of the Wistar strain were trained under a continu...

Drugs that alter dopamine transmission have opposite effects on reward and punishment learning. These opposite effects have been suggested to depend on dopamine in the striatum. Here, we establish for the first time the neurochemical specificity of such drug effects, during reward and punishment learning in humans, by adopting a coadministration design. Participants (N = 22) were scanned on 4 o...

Brain dopamine (DA) has been linked to error processing. Because high and low (vs medium) prefrontal cortex (PFC) DA levels may facilitate D2-receptor-related modulations of PFC neural activation patterns, we hypothesized that high and low DA predicts increased error-specific transitions of PFC activity. Male human participants (n = 169) were genotyped for the catechol-O-methyltransferase (COMT...

The effects of dopamine receptor blockade by sulpiride (D2-class antagonist) and sulpiride plus SCH 23390 (D1-class antagonist) on the V - log I function of the ERG b- and d-waves were investigated in dark adapted frog eyes. We observed that sulpiride enhanced the amplitude of the suprathreshold b- and d-waves in the lower intensity range, where the responses were mediated by rods, but diminish...