Somatostatin induces striatal dopamine release and contralateral turning behaviour in the mouse

Application of somatostatin to the striatum of the anaesthetized rat has previously been shown to elicit large increases in extracellular levels of dopamine and GABA via a glutamate-dependent mechanism. These actions have been ascribed to the SSTR2 receptor. Here we describe experiments designed to investigate whether these effects occur in C57Bl6 mice and if they elicit rotational behaviours associated with increased dopamine in the striatum. Application of somatostatin resulted in increased concentrations of dopamine in striatum, hippocampus and amygdala of anaesthetized mice. Unilateral striatal infusions of the peptide by retrodialysis increased locomotion. Application of N-methyl-D-aspartate and AMPA to the freely-moving mouse striatum resulted in increased dopamine release; however, only AMPA caused increased locomotion. These results further confirm that somatostatin can play a role in the control of locomotor function by modulating striatal dopamine release.