Ample evidence demonstrates that fear learning contributes significantly to many anxiety pathologies including
post-traumatic stress disorder (
PTSD). The
endocannabinoid (eCB) system may offer therapeutic benefits for
PTSD and it is a modulator of the hypothalamic pituitary adrenal (HPA) axis. Here we compared the separated and combined effects of blocking
glucocorticoid receptors (GRs) using the GR antagonist
RU486 and enhancing CB1r signaling using the CB1/2 receptor agonist WIN55,212-2 in the CA1 and basolateral amygdala (BLA) on the consolidation of traumatic memory. Traumatic memory was formed by exposure to a severe footshock in an inhibitory avoidance apparatus followed by exposure to
trauma reminders. Intra-BLA
RU486 (10ng/side) and WIN55,212-2 (5μg/side) administered immediately after
shock exposure dampened the consolidation of the memory about the traumatic event and attenuated the increase in acoustic startle response in rats exposed to
shock and reminders. In the CA1, WIN55,212-2 impaired consolidation and attenuated the increase in acoustic startle response whereas
RU486 had no effect. The effects of WIN55,212-2 were found to be mediated by CB1 receptors, but not by GRs. Moreover, post-
shock systemic WIN55,212-2 (0.5mg/kg) administration prevented the increase in GRs and
CB1 receptor levels in the CA1 and BLA in rats exposed to
shock and reminders. The findings suggest that the BLA is a locus of action of
cannabinoids and
glucocorticoids in modulating consolidation of traumatic memory in a rat model of
PTSD. Also, the findings highlight novel targets for the treatment of emotional disorders and
PTSD in particular.