ABSTRACT
Objective: To explore the difference in response to aversive stimulation and the expression of CaMK-2β in the lateral habenula between male and female mice. Methods: Male and female mice were given the non-condition stimulation with electric shock associated with the condition-stimulation with the light and tone context. After 24 hours, the mice were placed into the stimulation context and their responses were recorded and analyzed. At 48 hours after non-condition stimulation, the effects on extinction were observed in the male and female mice. Immunohistochemical method was used to detect the number of CaMK-2β positive cells in the lateral habenula nucleus. The expression of CaMK-2β protein in the lateral habenula was detected by Western blot. Results: Female mice were more sensitive to context cue compared with the male mice. Similarly, the female mice were more tolerant to extinction than their male counterparts. Consistently, at 48 hours after aversive stimulation, the CaMK-2β-positive cells in lateral habenula of female mice outnumbered those of the male mice. Additionally, the expression of CaMK-2β in habenula protein was higher in the female mice than in the male mice after aversive stimulation. Conclusion: Male and female mice showed different responses to the same stress stimulation, which determined the consolidation to stress information. The sex difference in aversive stimulation may contribute to the expression of CaMK-2β in the lateral habenula.