Functional dissection of neural circuitry using a genetic reporter for fMRI.

The complex connectivity of the mammalian brain underlies its function, but understanding how interconnected brain regions interact in neural processing remains a formidable challenge. Here we address this problem by introducing a genetic probe that permits selective functional imaging of distributed neural populations defined by viral labeling techniques. The probe is an engineered enzyme that transduces cytosolic calcium dynamics of probe-expressing cells into localized hemodynamic responses that can be specifically visualized by functional magnetic resonance imaging. Using a viral vector that undergoes retrograde transport, we apply the probe to characterize a brain-wide network of presynaptic inputs to the striatum activated in a deep brain stimulation paradigm in rats. The results reveal engagement of surprisingly diverse projection sources and inform an integrated model of striatal function relevant to reward behavior and therapeutic neurostimulation approaches. Our work thus establishes a strategy for mechanistic analysis of multiregional neural systems in the mammalian brain.

Parental attitudes toward bariatric surgery in adolescents with obesity.

BACKGROUND: Parental underestimation of the severity and risks of their child's obesity and parents' potential implicit weight bias contribute to the reluctance to consider bariatric surgery for their adolescent children with obesity. Despite evidence for safety and efficacy of bariatric surgery in adolescents, pediatric providers may be hesitant or uncomfortable to discuss the benefits and refer patients for surgical evaluation. Understanding these barriers is an essential step toward effective long-term care in this patient population. OBJECTIVES: We hypothesized that parental views on bariatric surgery are primarily influenced by personal experiences with bariatric surgery, their implicit bias, understanding of health risks of obesity, and counseling by pediatric providers. SETTING: Data were collected and analyzed at an academic medical center in the United States. METHODS: After a retrospective chart review of 192 adolescents with obesity, a telephone survey of patients' parents was conducted. RESULTS: Parents of 71.4% of patients who received outpatient weight loss counseling had accurate recollection of that event. Only 12.8% of parents who were referred to lifestyle programs successfully enrolled. Neither prior personal exposure to bariatric surgery nor enrollment of the child in a lifestyle program increased parents' likelihood to consider bariatric surgery for their child (P = .10 and .70, respectively). Most parents (84.6%) who were counseled by their pediatric provider about bariatric surgery would consider it, compared with only 34.5% of the parents who did not receive counseling (P < .001). CONCLUSIONS: Counseling by pediatric providers, not involvement in lifestyle programs or exposure to bariatric surgery, increased parents' willingness to consider bariatric surgery for their child. Given the current recommendations to incorporate bariatric surgery as a treatment modality in severe adolescent obesity, earlier counseling about the role of surgery by pediatric providers is essential. More detailed provider education on the current state of bariatric surgery in the treatment of severe adolescent obesity is also necessary.