TREK-1 is a postassium channel that is constitutively leaky, thereby maintaining resting membrane potential. Mechanical membrane stretching and certain anaesthetics can open the channel, thus greatly reducing neuronal excitability. TREK-1 is not a classic cannabinoid receptor but its activity is modulated by cannabinoids. Since cannabinoids have a physiological effect on TREK-1 it is effectively a cannabinoid receptor.
TREK-1 channels are found in a variety of tissues, but are particularly abundant in the brain and heart and are seen in various types of neurons.
Pertwee, R.G., Howlett, A.C., Abood, M.E., Alexander, S.P.H., Di Marzo, V., Elphick, M.R., Greasley, P.J., Hansen, H.S., Kunos, G., Mackie, K., et al. (2010). International Union of Basic and Clinical Pharmacology. LXXIX. cannabinoid receptors and their ligands: beyond CB₁ and CB₂. Pharmacol. Rev. 62, 588–631.