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Critical Reviews™ in Neurobiology

ISSN for PRINT: 0892-0915

Institutional price:	$649.00
Issues per year:	4

Best Paper Award Selection - Editorial Board Site

2004, Volume16

194 pages

DOI: 10.1615/CritRevNeurobiol.v16.i12

Issue price - $252.00

Brain Neurosteroids in Gender-Related Aggression Induced by Social Isolation

Graziano Pinna
Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA

Roberto Carlos Agis-Balboa
Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA

Mohemed-Salim Doueiri
Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA

Alessandro Guidotti
The Psychiatric Institute, Department of Psychiatry, University of Illinois at Chicago, Chicago Illinois, USA

Erminio Costa
The Psychiatric Institute, Department of Psychiatry, University of Illinois at Chicago, 1601 W. Taylor St., Chicago IL 60612, USA

ABSTRACT

Genetic, environmental, or hormonal factors and their interactions have been implicated in the expression of gender-related aggressive behavior in humans. Several independent lines of evidence support the role of hormonal and environmental factors in the aggressive behavior of experimental animals. Social isolation (SI) for 2−4 weeks in male but not in female mice results in the expression of aggression to a same-sex intruder. Long-term treatment (3 weeks) with anabolic steroids during SI in female mice induces aggressive behavior toward a male intruder of a severity similar to that observed in socially isolated (SI) male mice. The induced aggression in male and female mice is associated with a decrease of brain allopreg-nanolone (Allo). In SI male mice, aggression can be prevented by treatment with L-methionine (MET), which has also been shown to decrease reelin and GAD₆₇ mRNA expression and maintain normal brain Allo content. The histone deacetylase inhibitor valproic acid can reverse this process, suggesting that histone tail acetylation may reverse the action of MET.
We conclude that during social isolation, aggression can be controlled either by preventing Allo downregulation (e.g., by treatment with MET) or by direct administration of Allo or of agents (e.g., fluoxetine) that upregulate brain Allo content in SI mice.