Species differences in anxiety-related responses in male prairie and meadow voles: the effects of social isolation.
Prairie (Microtus ochrogaster) and meadow voles (M. pennsylvanicus) are closely related species that differ in life strategy and social behaviors, and thus provide an excellent comparative model for the study of neuronal and hormonal mechanisms underlying behavior. In the present study using the elevated plus maze (EPM) test, we found that male prairie voles entered the open arms of the EPM more and remained there longer, and showed a higher level of overall locomotor activity than did male meadow voles. In addition, two weeks of social isolation induced an increase in open arm entries in prairie, but not meadow, voles. Prairie voles also had a higher level of circulating corticosterone compared to meadow voles, and the EPM test increased circulating corticosterone in prairie voles. Finally, social isolation coupled with the EPM test influenced Fos-immunoreactive expression in several brain areas, including the medial preoptic area, ventromedial hypothalamus, amygdala, and prefrontal cortex differently between the two species. Together, these data indicate a neural circuit involved in mediating anxiety-associated behavior in voles, and that the functioning of this circuit is influenced by social environment differently between social and non-social species.
Stowe
Jennifer R
JR
Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA.
Liu
Yan
Y
Curtis
J Thomas
JT
Freeman
Marc E
ME
Wang
Zuoxin
Z
D000818:Animals; D001007:Anxiety / Q000378:metabolism / Q000503:physiopathology*; D003411:Arvicolinae / Q000145:classification* / Q000502:physiology*; D002452:Cell Count / Q000379:methods; D003345:Corticosterone / Q000097:blood; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D018782:Maze Learning / Q000502:physiology; D009043:Motor Activity / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D011863:Radioimmunoassay / Q000379:methods; D012934:Social Isolation / Q000523:psychology*; D013045:Species Specificity; D013997:Time Factors
D016760:Proto-Oncogene Proteins c-fos; D003345:Corticosterone