Dr. Morales’ lab is investigating the molecules, cells and neuronal pathways central to the neurobiology of drug addiction. Towards this end, the lab applies anatomical, cell molecular, cell biological and electrophysiological experimental approaches. The research focus on two issues: what is the brain circuitry through which addictive drugs have their habit-forming actions, and what are the neuroadaptations in this circuitry that accompany the transition from recreational to compulsive drug-taking?

Accumulating evidence indicate that the ventral tegmental area (VTA) plays a role in goal-directed behavior and in reward processing to natural rewards and to several drugs of abuse. Therefore, the lab is investigating the neuronal properties and synaptic connectivity of the VTA to gain a better understanding of the interactions of the VTA with other brain structures in the processing and integration of information underlying behaviors associated with the neurobiology of drugs of addiction. Two populations of VTA neurons, dopaminergic neurons and GABAergic neurons, have been extensively characterized. Unexpectedly the work has recently shown that glutamatergic neurons are also present in the VTA. The lab is currently exploring the neuronal connectivity of VTA glutamatergic neurons and their participation in animal behavior.

Clinical observations and results from animal models indicate that behaviors associated with intake of drugs of abuse are affected by stress. The neuronal pathways, neurons, and neurotransmitters that mediate interactions between stress and drugs of abuse are not well characterized. In this regard, work from the laboratory has provided evidence indicating synaptic connectivity between the reward and the stress systems at the level of the VTA