3D Reconstruction of VTA GABA Neuron Projections in the Brain

This project is for any student interested in the brain, biopsychology, biomedical sciences, behavior, or addiction. My laboratory studies the neural circuits responsible for drug use disorders and addiction. We have recently examined how GABA neurons in the ventral tegmental area (VTA) influence reward seeking, particularly those VTA GABA neurons that project to the anterior cingulate cortex (ACC). GABA is the primary inhibitory neurotransmitter of the brain and altered GABA signaling is the primary mechanism responsible for the effects of CNS depressants, anti-anxiety medications, and alcohol. The ACC has a prominent role in the executive decision making, and influences how an animal chooses between competing rewards, for example, choosing between a large reward that’s difficult to obtain or small reward that is easier to acquire. These circuits play a critical role in an animal’s survival as it helps them calculate relative costs versus benefits in seeking out rewards and shapes their behavior towards the rewards that are most cost effective. In addiction these circuits are altered and may contribute to the poor decision making often observed in addicts, such as choosing immediate access to the drug over longer-term benefits (e.g., health and financial security). We have found that VTA GABA neurons project widely throughout the brain, including to the ACC and prefrontal cortical areas, as well as other regions including the nucleus accumbens, amygdala and dorsal striatum which contribute to reward, fear memories and habit formation, respectively. Importantly, it appears that these neurons branch, such that a single VTA GABA neuron may innervate multiple brain regions. We hypothesize that this branching allows the VTA to regulate multiple aspects of reward seeking and coordinates the relative contributions of several brain regions to shape the behavior. To better understand these circuits, the student will examine the neuroanatomy of VTA GABA neurons using advanced viral tracing methods to obtain a 3D reconstruction of these neurons in the rat brain. By having a clear map of where these neurons project, we can better understand their role in reward seeking and addiction. 

1. Project report (~5 pages).
2. Draft of methods section in manuscript.
3. Poster to present at the Undergraduate research day.

1. Meet with Dr. Bass to discuss project, background, timeline, training schedules, and milestones.
2. Finish training sessions in environmental health and safety.
3. Read relevant background materials (e.g., review articles and research articles, two are attached here, others will be provided by Dr. Bass)
4. Read relevant manuals and protocols. 

Article 1

Article 2

neuroscience, psychology, addiction, behavior, anatomy, pharmacology, toxicology