Pridopidine (ACR16) belongs to a new pharmacological class of agents affecting 
the central nervous system called dopaminergic stabilizers. Dopaminergic 
stabilizers act primarily at dopamine type 2 (D(2)) receptors and display 
state-dependent behavioural effects. This article aims to give an overview of 
the preclinical neurochemical and behavioural in vivo pharmacological properties 
of pridopidine. Pridopidine was given s.c. to male Sprague-Dawley rats 
(locomotor, microdialysis and tissue neurochemistry) and i.p. to Swiss male mice 
(tail suspension test). Pridopidine dose-dependently increased striatal tissue 
levels of the dopamine metabolite 3,4-dihydroxyphenylalanin (ED(50)=81 
micromol/kg), and prefrontal cortex dialysate levels of dopamine and 
noradrenaline as measured by high performance liquid chromatography. The agent 
reduced hyperlocomotion (d-amphetamine: ED(50)=54 micromol/kg; MK-801: ED(50)=40 
micromol/kg), but preserved spontaneous locomotor activity, confirming 
state-dependent behavioural effects. In addition, pridopidine significantly 
reduced immobility time in the tail suspension test. We conclude that 
pridopidine state-dependently stabilizes psychomotor activity by the dual 
actions of functional dopamine D(2) receptor antagonism and strengthening of 
cortical glutamate functions in various settings of perturbed neurotransmission. 
The putative restoration of function in cortico-subcortical circuitry by 
pridopidine is likely to make it useful for ameliorating several neurological 
and psychiatric disorders, including Huntington's disease.