Biomedical subjects

M L Wadenberg

Publications and source records attributed to M L Wadenberg.

22 records · Page 2Linked to original sources

PubMed1991

Effects of raclopride and haloperidol on spontaneous motor activity and on conditioned avoidance behavior in rats. A comparison of potency, efficacy and time-course of action.

The spontaneous locomotor activity of rats was used as an index of centrally mediated effects of raclopride (CAS 84225-95-6). The results indicate a duration of less than 2 h after s.c. administration of 2 mumol kg-1. In support of a rapid first-pass metabolism in the rat, the effect was considerably weaker after i.p. administration. This difference was further supported by comparing the dose-effect curves after s.c. and i.p. raclopride administration. Haloperidol (CAS 52-86-8) appears to be slightly more potent than raclopride, the estimated ED50 values being 0.15 and 0.24 mumol kg-1 s.c., respectively. Both compounds (s.c. administration) produced a complete suppression of the conditioned avoidance behavior with approximately the same potency. As assessed in the latter situation, the duration of the effects of raclopride is considerably shorter than that of haloperidol.

Animals↗

PubMed1990

Suppression of conditioned avoidance behavior by the local application of (-)sulpiride into the ventral, but not the dorsal, striatum of the rat.

The local application of (-)sulpiride, 200 ng side-1, into the nucleus accumbens produced a suppression of conditioned avoidance behavior in male rats, 10 and 90 min after injection. The decrease in avoidance behavior was accompanied by a decrease in motor activity, as evidenced by changes in the number of intertrial crosses. When injected into the dorsolateral neostriatum, or the amygdala, (-)sulpiride produced a suppression of conditioned avoidance behavior at the 90-min time interval only. Considering diffusion from the injection site, as indicated by an increase in local dopamine turnover [(DO-PAC + HVA) DA-1], the effects obtained in the dorsolateral neostriatum, and possibly also the amygdala, 90 min after injection could be due to diffusion to the nucleus accumbens. The local application of (-)sulpiride into the posterior neostriatum, or into the prefrontal cortex, produced no statistically significant effect on conditioned avoidance behavior 10 or 90 min after injection. It is concluded that the performance of conditioned avoidance behavior in the rat is critically dependent on an intact dopaminergic neurotransmission in the nucleus accumbens or adjacent areas of the ventral striatum.

Amygdala↗

PubMed1989

Effects of 8-OH-DPAT on motor activity in the rat.

The administration of 8-OH-DPAT to rats produced a dose-dependent suppression of spontaneous locomotor activity in an open field arena. 8-OH-DPAT was administered in the dose range 12.5-1,600 micrograms.kg-1 SC. Vertical activity ("rearing") was more sensitive to the treatment than horizontal activity ("locomotion"), both in terms of potency and efficacy. The activity along the walls of the open field arena ("peripheral activity") was increased, and the rearing activity was decreased, relative to total horizontal activity and total activity, respectively. There were no effects by 8-OH-DPAT on treadmill locomotion. The rectal temperature was decreased by 8-OH-DPAT administration, not only in animals tested in the open field, but also in animals with an increased body temperature, produced by treadmill locomotion.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1988

Suppression of conditioned avoidance by 8-OH-DPAT in the rat.

Rats were trained to perform an aversely motivated discriminative task in a shuttle-box. The conditioned avoidance response was selectively suppressed by 8-OH-DPAT in a dose-dependent manner (25-100 micrograms.kg-1). There were no statistically significant deficits in discriminative performance. The present results suggest antipsychotic-like properties of 8-OH-DPAT.

8-Hydroxy-2-(di-n-propylamino)tetralin↗