“…Molecular, neurophysiological, and neurobehavioral experimentation ( Clarac and Pearlstein, 2007 ) on the mechanisms of natural and drug-sensitive reward profits from a highly modular neural structure, conserved monoaminergic, neuromodulatory systems, a relatively small number of large and individually identifiable neurons, and high sensitivity toward human drugs of abuse. Amphetamine ( Alcaro et al, 2011 ), cocaine ( Nathaniel et al, 2012a , b ), morphine ( Nathaniel et al, 2010 ), and cathinones (Gore et al, unpublished data) exhibit potent psychostimulant properties, which sensitize with repeated exposure ( Nathaniel et al, 2010 , 2012b ; Dziopa et al, 2011 ). Moreover, in a conditioned place preference paradigm (CPP), these substances trigger the formation of strong associations between drugs and the cues with which they are paired ( Panksepp and Huber, 2004 ; Nathaniel et al, 2009 ).…”