Dopaminergic neurons in the brainstem ventral regimental area are proposed to be involved in positive affect (joy). a. Propose two types of experiments that could be used to activate these neurons (one on a short time-scale and one on a longer time-scale). Describe the experiments in sufficient detail (mouse lines (genotypes to target specific cell types), viruses, and injections) to demonstrate understanding of the technique, its pros, and its cons b. Inhibition of these cells using either opto- or chemogenetics would be proposed to lead to a negative affect. Describe three tests that could be used to assay negative affect in these mice