Bilateral microinjection of the CB1 agonist, Win 55212-2, produced antinociceptive effects in the tail-flick assay, which was blocked by a CB1, but not CB2 receptor antagonist, suggesting that activation of CB1 receptors in this region may be an important anatomical site for the production of cannabinoid antinociception (Hasanein et al., 2007). Interestingly, stress-induced analgesia is partially blocked by administration of the CB1 receptor antagonist SR141716 into the BLA (Connell et al., 2006). However, blockade of CB1 receptors in the right BLA did not alter fear-conditioning-induced analgesia in rats (Roche et al., 2007).
