Dorsal hippocampus cannabinoid type 1 receptors modulate the expression of contextual fear conditioning in rats: Involvement of local glutamatergic/nitrergic and GABAergic neurotransmissions.

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.