It is a great pleasure to discuss this presentation by Richard Sun, a tremendously promising neurosurgery resident in the Hofstra Northwell Program. I want to congratulate Richard first on choosing to work in the lab of Anne Churchland, one of the brightest neuroscientists of our time. Secondly, I congratulate Richard on this high-quality work, which has earned him the ASSFN's Philip L. Gildenberg Resident Award. Neurological and psychiatric disorders are recognized as disorders of brain networks, not as disorders of singular spots in the brain. A better understanding of these networks and their dysfunction will lead to better circuit-based therapeutics, including surgical neuromodulation techniques such as deep brain stimulation. A canonical circuit motif that is critical to the regulation of behavior is the loop connecting the cortex to the striatum and basal ganglia onto thalamus and back to cortex. These so-called CSTC pathways often demonstrate dysfunction in neuropsychiatric disorders and can thus be targeted with DBS or other techniques for therapeutic modulation. Anne Churchland and colleagues used a mouse model to dissect and study CSTC circuitry. They developed a viral intersection strategy using a retrograde virus, CAV2, and a blood-brain barrier permeable AAV variant, AAVPHPEB, to express genetically encodable calcium indicators in corticostriatal and corticothalamic projections. They used a wide-field fluorescence microscopy system to visualize evoked activity in behaving mice. They then trained the animals in an auditory two-alternative forced-choice task that required them to look for water reward in response to auditory clicks while undergoing wide-field calcium imaging. Their reported results regarding predictions of sensory cortical activity based on corticostriatal activity demonstrate the strength of this approach but do appear preliminary at this point. Their future planned analyses using encoding and decoding strategies, as well as optogenetic manipulations, will likely take full advantage of their experimental setup. Once again, I congratulate Richard on his outstanding work and for winning the great honor of the Guildenberg Award, and wish him the best for his bright neurosurgical career ahead.

Richard Sun

neurosurgery resident

Hofstra Northwell Program

CSTC pathway

neurological and psychiatric disorders