“The cannabinoid receptor type 1 (CB1) is highly expressed in the dorsal portion of hippocampus – a brain region that has been involved in the control of conditioned emotional response (CER) in the contextual fear conditioning (CFC) model.
These responses are characterized by increased freezing behavior and autonomic parameters. Moreover, CB1 receptors activation negatively modulate the release of several neurotransmitters, including glutamate and GABA, which also have been related to modulation of CER. Therefore, our aim was to investigate the involvement of CB1 receptors in the dorsal hippocampus on CER expression.
Our results suggest that increased CER evoked by CB1 blockade in the dorsal hippocampus depends on NMDA receptor activation and NO formation. Moreover, a fine-tune control promoted by GABAergic and glutamatergic mechanisms in this brain area modulate the CER after CB1 blockade.”