δ-opioid receptors are primarily sensitive to opioids and enkephalins. δ-opioid receptors are not classic cannabinoid receptors but their activity is modulated by cannabinoids. Since cannabinoids have a physiological effect on δ-opioid receptors they are effectively cannabinoid receptors.

Cav3.3 is a calcium channel of the T-type that is involved in many brain processes. Contrary to other calcium channels Cav3.3 is activated by relatively low/negative voltages.