Successive negative contrast in one-way avoidance: effect of thiopental sodium and chlorpromazine

European Journal of Pharmacology
C TorresA. Maldonado

Abstract

The successive negative contrast effect on one-way avoidance was induced by shifting rats from a large reward (30 s spent in the safe compartment after completion of the avoidance response, pre-shift phase) to a small reward (1 s, post-shift phase). Under these conditions, the previously learned avoidance response deteriorated (negative contrast) when compared to a control group for which 'safe time' remained constant throughout the experimental situation (1 s). Thiopental sodium at a dose of 5 or 10 mg/kg, but not at 1, 2, 15 or 20 mg/kg i.p., abolished the negative contrast effect, and did not affect performance of the one-way avoidance task. Similar results were found when rats were treated with diazepam (1 mg/kg i.p.). Chlorpromazine at a dose of 0.5 or 1 mg/kg i.p. did not affect negative contrast, although at higher doses (2 or 3 mg/kg) there was an increase in the number of trials needed to reach the criterion for learning the avoidance response. This increase was evident in both pre-shift and post-shift phases, although only in the experimental situations involving a low level of reinforcement (1 s in the safe compartment). On the basis of these results, we tentatively suggest that the successive negative contrast effec...Continue Reading

References

Sep 1, 1992·Pharmacology, Biochemistry, and Behavior·A MoralesA Maldonado
May 1, 1992·Pharmacology, Biochemistry, and Behavior·C F FlahertyP S Grigson
Jan 1, 1990·Pharmacology & Therapeutics·C F Flaherty
Jan 1, 1985·Neuroscience and Biobehavioral Reviews·D Treit
Apr 1, 1985·The American Psychologist·N E Miller
May 1, 1985·Pharmacology, Biochemistry, and Behavior·D Wirtshafter, K E Asin
Jan 1, 1980·Psychopharmacology·C F Flaherty, C D Driscoll
Jan 1, 1994·Annual Review of Neuroscience·R L Macdonald, R W Olsen
Jul 14, 1995·European Journal of Pharmacology·C TorresA Maldonado

❮ Previous
Next ❯

Citations

Apr 2, 2003·Pharmacology, Biochemistry, and Behavior·Ruey-Ming Liao, Feng-Jung Chuang
Nov 29, 2001·The Spanish Journal of Psychology·P Herreros de Tejada, C Muñoz Tedó
Feb 28, 2007·Physiology & Behavior·A MaldonadoA Fernández-Teruel

❮ Previous
Next ❯

Related Concepts

Related Feeds

Antipsychotic Drugs

Antipsychotic drugs are a class of medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia and bipolar disorder. Discover the latest research on antipsychotic drugs here