afferents to the BLA. The application of a psychological stressor results in increased FAAH activity, which reduces AEA/CB1 receptor signaling, and disinhibits excitatory transmission in the BLA. As a result, the neural activity of BLA projection neurons that indirectly communicate with the PVN is increased. These data support the “gatekeeper” hypothesis of endocannabinoid regulation of the HPA axis (Patel et al., 2004), but demonstrate that in addition to the PVN (Di et al., 2003), the BLA is an important structure involved in the suppression of the neuroendocrine response to stress by endocannabinoid signaling. Taken together, the present data indicate that stress-induced regulation of endocannabinoid signaling within the amygdala could be an important determinant in the neuroendocrine, and possibly emotional, responses to aversive, environmental stimuli.
