Mouse Study Links Cannabinoid to Threat Responses

A mouse study found that the synthetic cannabinoid CP55940 heightened some defensive responses to a predator-like odor and increased activity in somatostatin-producing neurons in the central amygdala, a brain region involved in emotional responses. The findings point to a possible circuit mechanism, not proof of how cannabis affects anxiety in people. ^[1][2]

Researchers reported that the drug’s effects on neuron activity varied with dose. When they blocked the neurons’ synaptic output, the cannabinoid no longer increased odor avoidance to the same extent, though the intervention did not prevent increased freezing. The results suggest these neurons contribute to threat avoidance in this mouse experiment. ^[2]

The study used CP55940, a potent synthetic cannabinoid, rather than testing cannabis use in people. Its findings therefore do not establish that the same brain mechanism explains anxiety in humans or demonstrate a treatment for it. ^[1][2]