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Biomedical subjects

D J Albert

Publications and source records attributed to D J Albert.

At least 73 records · Page 4Linked to original sources
PubMed1980

Suppression of mouse killing by lateral hypothalamic infusion of atropine sulfate in the rat: a general behavioral suppression.

Male hooded rats which had been induced to kill mice by food deprivation had intracranial cannulas implanted into the lateral hypothalamus. Injections of 3 microliter to each side of the brain blocked mouse killing in 12 out of 15 animals when the injected substance was the general blocking agent lidocaine. Atropine sulfate produced a significant suppression of mouse killing at a dose of 15 microgram to each hemisphere but not with doses of 1.8 or 6.0 microgram. The 15 microgram but not the 1.8 microgram dose also suppressed food intake. It is argued that the cholinergic antagonist atropine sulfate only suppresses mouse killing at high doses which produce a general suppression of behavior.

Aggression↗
PubMed1978

Hyperreactivity, muricide, and intraspecific aggression in the rat produced by infusion of local anesthetic into the lateral septum or surrounding areas.

Intracranial infusions of a local anesthetic (lidocaine, 2%) were made bilaterally (4 microliter over 20 min) through permanently implanted cannulas ending in the lateral septum or adjacent areas. Increases in irritability and reactivity to the experimenter, muricide, and intermale aggression were produced by injections into the lateral septum and the region ventral to it. The increases in reactivity and interanimal aggresion occurred in varying degrees and were independent of one another, but intermale aggression occurred only in animals showing muricide. The most effective site for eliciting the entire spectrum of aggressive behaviors was the region ventral to the anterior septum. The region ventral to the posterior septum (medial preoptic area, anterior hypothalamic area, straia terminalis) was unique in that it tended to produce a high incidence of muricide, with only modest increases in reactivity. The lateral septum was moderately effective in producing the entire range of aggressive behaviors. No changes in behavior were noted with infusions into the medial septum or th medial forebrain bundle/lateral preoptic area ventrolateral to the septum. It is suggested that the hyperreactivity and irritability may be relat to hyperdefensiveness and that muricide and intermale aggression are points on a continuum of interanimal aggressiveness.

Aggression↗
PubMed1977

Suppression of VMH-lesion-induced reactivity and aggressiveness in the rat by stimulation of lateral septum, but not medial septum or cingulate cortex.

Animals made vicious with bilateral ventromedial hypothalamic lesions had bipolar electrodes implanted unilaterally in the lateral septum, medial septum, or cingulate cortex. Four days later, the animals' reactivity and aggressiveness were evaluated 5 min before, during, and 5 min after stimulation at 20 micronA (60 Hz, sine wave). Lateral septal stimulation suppressed reactivity and aggressiveness by almost 80% compared with pre- and poststimulation levels. Stimulation of neither the cingulate cortex nor the medial septum produced a change reliably different from that seen in unstimulated control animals. Further tests with stimulation of the lateral septum at the 20-micronA level showed that neither rewarding self-stimulation nor disruption of ongoing water drinking was produced. These results are congruent with evidence from lesion studies that the lateral septum normally acts to suppress reactivity and aggressiveness in the rat; they do not support previous suggestions that the medial septum is involved in the modulation of these behaviors.

Aggression↗
PubMed1977

Reactivity and aggression in the rat: induction by alpha-adrenergic blocking agents injected ventral to anterior septum but not into lateral septum.

Intracranial injections were made bilaterally through permanently implanted cannulas ending in the lateral septum or in the region ventral to the anterior septum. The rats were first screened with injections of a local anesthetic, lidocaine, which blocks both synaptic and axonal conduction. Those animals that showed an increase in reactivity and aggression were then injected with a synaptic transmitter blocking agent. The results showed that transmitter blocking agents reproduced the effect of the local anesthetic only in the region ventral to the anterior septum and that alpha-adrenergic (phentolamine, tolazoline), but not beta-adrenergic (propranolol, hydralazine), cholinergic (atropine, hyocine), or dopaminergic (haloperidol) blocking agents were effective. These results suggest that synapses in the forebrain system controlling reactivity and aggression are alpha-asrenergic and are located in the region ventral to the anterior septum just lateral to the diagonal band of Broca. The septum itself may be involved only to the extent that it is traversed by fibers of passage.

Adrenergic alpha-Antagonists↗