Answer to Question 1
Answer: The ventral tegmental area (VTA) projects to the nucleus accumbens (NAcc) via the mesolimbic dopamine pathway. Increases of dopamine within the NAcc are reinforcing. Natural reinforcers (food for a hungry rat) will elicit this increase in DA, as will drugs of abuse such as amphetamine that are also reinforcing (i.e., rats will make a response that delivers the drug into their blood stream or directly into the NAcc).
Answer to Question 2
Answer: NMDA receptors are found in the hippocampus, are activated by glutamate and depolarization, and control a calcium channel in the postsynaptic dendrite. Blockade of NMDA receptors, using AP5, blocks the formation of LTP.
