NMDA receptors are sensitive to the neurotransmitter glutamate. NMDArs are best known for their function in neurons as coincidence detectors and consequently their role in learning and memory. NMDArs are not classic cannabinoid receptors but their activity is modulated by cannabinoids. Since cannabinoids have a physiological effect on NMDArs they are effectively cannabinoid receptors.
NMDArs are present in many types of neurons and are particularly highly expressed in brain regions involved in learning and memory.
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.