Figure 8.

A hypothetical model of polysynaptic effects leading to METH-induced striatal GLU release. Degree of activity is represented by thickness of the arrows. A, Normal conditions, under which basal activity of the substantia nigra regulates both DA and GLU release in the striatum. B, Effects of METH. DA release in the striatum increases GABAergic release in the SNr, which inhibits nigrothalamic outflow leading to a disinhibition of thalamocortical afferents and subsequent activation of the corticostriatal GLU pathway.