Section 1.1, describes the basic anatomy of midbrain dopamine (DA) system. Due to the heterogeneous nature and wide projection, I have summarized the essential points in this section. Section 1.2 focuses on the role of DA for motivated behaviour and change in the striatum during learning is in order, hence the DA role can be made clear. The chapter focuses on nucleus accumbens (NAc) DA changes due to the massive projection from ventral tegmental area(VTA). Special emphasis is given to the DA role in reward processing and avoidance learning. Section 1.3 starts with the history of intracranial...