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P F Brain

Publications and source records attributed to P F Brain.

At least 73 records · Page 4Linked to original sources
PubMed1984

Comparison of the influence of the opiate delta receptor antagonist, ICI 154,129, and naloxone on social interaction and behaviour in an open field.

The influence of a novel opiate delta receptor antagonist, ICI 154,129, and naloxone on social interaction and on behaviour in an open field were compared. At a dose thought to optimally block the delta receptor, ICI 154,129 produced open field behaviour typical of a non-emotional animal: this drug decreased social investigation and the latency to attack. In contrast, naloxone was largely without effect in these tests.

Animals↗
PubMed1984

An ethological analysis of the influence of perinatally-administered diazepam on murine behaviour.

A number of studies have found that the perinatal exposure of rodents to various tranquilizing agents alters their adult behaviour. Given the known anti-aggressive influence of acute doses of diazepam it was hypothesized that, when administered during pregnancy, this drug would change the adult social behaviour. The social interactions of adult male mice whose mothers were treated with diazepam or appropriate controls during pregnancy were video-taped and subjected to an ethological analysis that involved counting the incidences of 43 distinct postures. Prenatal but not postnatal diazepam treatment was associated with a large increase in the incidence of the sideways offensive posture. No significant differences resulted, however, in the case of other postures; in general exposure to prenatal diazepam produced few changes in adult social behaviour.

Aggression↗
PubMed1983

The effects of differential housing, castration and steroidal hormone replacement on attacks directed by resident mice towards lactating intruders.

Group-housed castrated (but not intact) males show high incidences of attack on lactating (but not non-lactating) female intruders. In Experiment 1, responses by isolated and group (in 3's)-housed intact and castrated males to lactating intruders were studied. The latter males were given sham, testosterone (T) or estradiol (E2) implants before testing. Castration augmented attack by animals in both housing conditions, confirming that intra-group fighting could not account for androgen-related changes in fighting behaviour in group-housed animals. Both T and E2 implants suppressed attack in animals in both housing conditions. Consequently, Experiment 2 evaluated the influence of three dose levels of T, E2 and DHT (dihydrotestosterone), in attack by castrated group-housed male residents on lactating intruders. Treatment of castrated males with T or E2 (but not DHT) inhibited attack in these animals. These findings provide support for the idea that aromatization is also a prerequisite for the inhibitory action of T on male aggression towards lactating females.

Aggression↗
PubMed1981

Behavioral and adrenocortical reactivity in female mice following individual or group housing.

Female "TO" strain mice were individually or group-housed for different durations (7-196 days). Behavioral reactivity was assessed for 3 days in an open field and an emergence test. Plasma samples were later collected after 5 min exposure to ethyl ether vapor; these generated "stress" corticosterone values. "Basal" corticosterone titers were obtained from similar untested and unanesthetized categories of mice. "Ether-stress" values were obtained from a limited number of mice subjected to ether anesthesia but no behavioral testing. Neither the basal nor the stress adrenocortical activities of the 2 housing categories differed. Open-field ambulation increased with longer durations of isolation, whereas for grouped mice it remained approximately constant. Individually housed mice had significantly lower defecation scores and longer emergence times than group-housed mice. In sum, little support was provided for the view that isolation is stressful.

Animals↗
PubMed1979

Effects of lithium chloride injections on rank-related fighting, maternal aggression and locust-killing responses in naive and experienced 'TO' strain mice.

Three experiments investigated lithium chloride's (LiCl) effects on three forms of aggression in male 'TO' strain mice. Models of aggression investigated, included attack by preisolated males on male conspecifics (rank-related or intermale fighting), attack by lactating females on male intruders (maternal aggression) and the locust-killing response (a form of predatory aggression?) In the first study, injections of naive male mice with 0.2 and 0.4 mEq of LiCl resulted in marked declines in rank-related fighting. The effects of this treatment on locust killing could not be assessed, as this activity was already at a low incidennce in controls. In a second experiment, LiCl injection had little influence on the locust-killing response in selected, experienced male killer mice. As in Experiment 1, rank-related fighting was suppressed by this treatment. The third experiment revealed that LiCl injections did not influence either maternal aggression or locust killing in naive females and predatory aggression in experienced-killer females. These results provide further support for the contention that these three behaviors have very different physiological bases. The data suggests that one should be cautious when extrapolating between different models of aggression even within the same species.

Aggression↗
PubMed1979

Sex steroid control of intermale fighting in mice.

The data presented here are based on over 700 mice and employed over 13,000 injections. The results obtained provide good evidence that the influences of sex steroids on fighting motivation in aggressive mice are discrete from the somatic influences of these hormones. Further, it seems possible that some of the effects of naturally occurring endogenous androgens in the mouse are consequent upon local neural aromatization of these compounds to estrogenic metabolites, before they exert an influence on aggressive motivation. It seems possible that this is a physiological effect as well as a consequence of pharmacological influence, as the doses of steroid employed in this present study are quite low. However, this model of hormone action cannot be the entire story, as 5 alpha DHT is behaviorally effective even though its A ring cannot be aromatized. Aggressive mice seem useful behavioral models for these effects. These studies indicate some of the likely sources of variability in the literature, as well as providing a number of considerations for clinical behavior therapy. They also indicate some of the features of steroid hormones (such as an aromatized A ring; the presence of a hydroxyl group at position 19; the influence of alpha hydroxyl groups, etc.) which may change the behavioral and somatic influences of these compounds.

Aggression↗