The SHR Y-chromosome increases testosterone and aggression, but decreases serotonin as compared to the WKY Y-chromosome in the rat model.
The Spontaneously Hypertensive Rat (SHR) model was used to test the hypothesis that a locus on the SHR Y-chromosome is responsible for increased aggression resulting from increased serum testosterone and decreased amygdala serotonin content compared to the WKY Y-chromosome. To examine the Y-chromosome in SHR and WKY males, consomic Y-chromosome strains were used (WKY.SHR-Y and SHR.WKY-Y). Novel resident intruder tests and intra-colony scarring behavioral paradigms were used to measure aggression in a colony environment. Both resident intruder test attack number and wounding, along with intra-colony scarring scores showed the colony males with the SHR Y-chromosome (SHR and WKY.SHR-Y strains) were more aggressive than the colony males with the WKY Y-chromosome (WKY and SHR.WKY-Y strains). The SHR Y-chromosome colony male animals also had significantly higher serum testosterone, as well as overall lower amygdala serotonin content than the WKY Y-chromosome colony male animals. The results suggest that these behavioral and physiological differences between the SHR and WKY strains are a result of a mutation in the non-pseudoautosomal region unique to the Y-chromosome.
Biology Department, The University of Akron, Akron, OH 44325-3908, USA. ely1@uakron.edu
Jonathan
J
Toot
Gail
G
Dunphy
Monte
M
Turner
Daniel
D
Ely
D000374:Aggression / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000502:physiology; D006799:Housing, Animal; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012701:Serotonin / Q000378:metabolism*; D013045:Species Specificity; D013739:Testosterone / Q000378:metabolism*; D014998:Y Chromosome / Q000235:genetics*
D012701:Serotonin; D013739:Testosterone