Strain-specific effects of inescapable shock on intracranial self-stimulation from the nucleus accumbens.
Responding for electrical stimulation from the nucleus accumbens was assessed in 3 inbred strains of mice (DBA/2J, C57BL/6J and BALB/cByJ) following exposure to uncontrollable footshock. While the operant response was most readily acquired in the DBA/2J strain, exposure to inescapable shock in this strain induced a marked deterioration of self-stimulation responding, which tended to dissipate over a 168-h period. In contrast to these mice, the stressor did not affect self-stimulation responding in the C57BL/6J strain, and produced a transient enhancement of responding in BALB/cByJ mice. It appears that although uncontrollable aversive events may engender an anhedonic effect, such an outcome is strain-dependent. These data suggest the importance of considering individual and genetic differences in the development of animal models of depression.
Zacharko
R M
RM
Department of Psychology, Carleton University, Ottawa, Ont., Canada.
Lalonde
G T
GT
Kasian
M
M
Anisman
H
H
D000818:Animals; D004597:Electroshock; D004924:Escape Reaction / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009714:Nucleus Accumbens / Q000502:physiology*; D012653:Self Stimulation / Q000502:physiology*; D012686:Septal Nuclei / Q000502:physiology*; D013045:Species Specificity