Cannabinoids and levodopa-induced dyskinesia

The endocannabinoid system modulates the release of excitatory and inhibitory neurotransmitters in several brain areas implicated in motor control. Cannabinoid and dopamine receptors are highly abundant and often co-expressed in the basal ganglia circuitry, and the cross talk between these two systems regulates short- And long-term synaptic plasticity in the striatum. Dysregulation of the endocannabinoid system has been reported in animal models of Parkinson's disease and parkinsonian patients and is exacerbated in dyskinetic states, following chronic levodopa administration. This chapter reviews recent investigations on the relationships between endocannabinoids and other neurotransmitter/neuromodulator systems in the basal ganglia, with the intent to underline their relevance for the pathophysiology of levodopa- induced dyskinesia and discuss new pharmacological approaches for their treatment.