The responsivity of the neuron(s) to electrical and synaptic stimuli is strictly dependent on its morphological features, which in turn, are deeply modified by drugs of abuse (Robinson and Kolb, 2004) and withdrawal from chronic treatment with opiates (Sklair-Tavron et al., 1996; Spiga et al., 2003, 2005), cannabis derivatives/analogs (Spiga et al., 2010), and psychostimulants (Robinson and Kolb, 1997) have been shown to produce reductions in DA cells size (Sklair-Tavron et al., 1996; Spiga et al., 2003), paralleled by persistently (Diana et al., 2006) altered patterns of synaptic connectivity, and spines density in the Nacc and Pfcx (Robinson and Kolb, 1997). These architectural changes would be expected to modify intrinsic spontaneous action potential generating capacity and responsiveness of the system to the TMS stimuli. Accordingly, realistic computational analysis (Spiga et al., 2010) of cannabis-dependent rats, generated by input of experimentally verified morphometrical and electrophysiological properties, predicts a lower action potential generation of Nacc medium spiny neuron (MSN). These results suggest that MSN, of cannabis-dependent rats are likewise hypofunctional. Considering that the main drive of these neurons is cortical glutamate (Glu;
