We have shown earlier that repeated exposure to restraint stress causes a progressive increase in 2-AG content in the amygdaloid region (Patel et al, 2005b; Rademacher et al, 2008). We extend these findings to show that this effect can be observed within the BLA subregion of the amygdala. No increases in 2-AG were observed after acute restraint stress, however, significant increases in 2-AG were observed after 10 consecutive restraint exposures. Furthermore, the effect is transient, with levels returning toward control by the end of the 10th restraint episode. These data suggest that repeated restraint stress confers BLA neurons with an enhanced capacity to transiently elevate 2-AG levels in response to subsequent restraint exposure.
