Cannabinoids have been shown to critically modulate cholinergic neurotransmission in the hippocampus, yet opposing effects of cannabinoid receptor 1 (CB1R) agonists on hippocampal synaptic acetylcholine (ACh) efflux have been reported. This study shows that administration of a synthetic CB1R agonist results in a biphasic, dose-dependent, effect on hippocampal ACh: a low (0.5 mg/kg, i.p.) and a high (5 mg/kg, i.p) dose of WIN55,212-2 induces a transient stimulation and a prolonged inhibition of hippocampal ACh efflux, respectively. Both effects of WIN55,212-2 are mediated through CB1 receptors coupled to Gi but involve different neuroanatomical sites. Thus, intrahippocampal infusion of the CB1R antagonist SR141716A or pertussis toxin...

In this overview we have summarized some aspects of our published work related to the effects of the endocannabinoid system on appetite and suckling. As noted also by several other groups we have found that anandamide, a major endocannabinoid, enhances appetite in mice. On partial or full food deprivation over 24 h the levels of 2-arachidonoyl glycerol (2-AG), a second major cannabinoid, are initially elevated in mouse brain; however, partial food deprivation over a longer period causes reduction of 2-AG levels. Blocking the endocannabinoid system with a CB1 antagonist on the 1st day after birth leads to inhibition of suckling; later administration also affects...