Rgs9-1 is expressed exclusively in retina, while Rgs9-2 is highly enriched in striatal regions of the brain. Rgs9 plays a role in striatal dopamine-mediated behavior [41] and has been shown to be a critical negative regulator of opiate action in vivo [42]. Rgs9 knockout rats exhibit normal locomotor activity, anxiety-like behavior, cued and contextual fear conditioning, startle threshold, and prepulse inhibition which suggest that Rgs9-2 is a potential therapeutic target for disorders involving motor or cognitive dysfunction [43]. Here, RGS9 is linked to Anxiety.