This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2018, Broadening Participation of Groups Under-represented in Biology. The fellowship supports a research and training plan for the Fellow that will increase the participation of groups underrepresented in biology. This project is aimed at understanding how and when different circuits in the brain interact to facilitate associative learning. All animals rely upon learned associations between environmental stimuli and the outcomes they predict for functions such as navigation, foraging, selecting mates, and avoiding predators. Associative learning requires coordination between multiple circuits in the brain and the neurotransmitters (signalling chemicals) to facilitate these behaviors. Therefore, to develop a better understanding of how the brain controls complex behaviors, it is necessary to determine how different brain circuits interact. This fellowship will support the research, training, and career advancement of a fellow from an ethnic group underrepresented in STEM, while also enabling the fellow to provide mentorship, outreach and educational tools to underserved high schools.
One neural pathway that plays a central role in mediating associative learning is the mesolimbic dopamine pathway, which projects from the midbrain to the striatum. Preeminent theories of dopamine's role in signaling learned associations between stimuli are based upon studies of mesolimbic dopamine neuron firing patterns during associative learning, and the assumption that cell firing and neurotransmitter release are correlated. Recent studies in brain slices, however, have demonstrated that acetylcholine, released by striatal cholinergic interneurons, can regulate dopamine neurotransmission at the axon terminal, effectively uncoupling dopaminergic neuron firing and neurotransmitter release. The fellow will address the need for systematic characterization of the function of this regulation mechanism, and its role in associative learning, by performing in vivo studies with the following objectives: 1) Determine how physiologically relevant cholinergic interneuron firing patterns modulate striatal dopamine release in vivo. 2) Determine how pauses in cholinergic interneuron firing, which are known to occur during associative learning, alter striatal dopamine release triggered by Pavlovian conditioned stimuli, and impact learning related behavior. Through this work, the fellow will receive technical training in the use of genetic tools to isolate specific cell populations, optogenetics, slice electrophysiology, mouse behaviour, and surgical techniques, as well as professional development support. Furthermore, the fellow will develop and employ a neuroscience workshop to immerse high school students from backgrounds underrepresented in science in the scientific process.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
