Figure 1 (continued).
B. Saal et al. (4) showed that on day one after drug administration, five drugs of abuse (i.e., amphetamine, cocaine, nicotine, ethanol, or
morphine) or a stressor produced LTP at excitatory synapses onto VTA DA neurons. By transiently activating DA transmission
to nucleus accumbens and other forebrain areas, this may trigger sensitization of drug “wanting.”