Michaela Guo

All Publications

• Opponent control of reinforcement by striatal dopamine and serotonin. Nature Cardozo Pinto, D. F., Pomrenze, M. B., Guo, M. Y., Touponse, G. C., Chen, A. P., Bentzley, B. S., Eshel, N., Malenka, R. C. 2024

  Abstract

  The neuromodulators dopamine (DA) and serotonin (5-hydroxytryptamine; 5HT) powerfully regulate associative learning1-8. Similarities in the activity and connectivity of these neuromodulatory systems have inspired competing models of how DA and 5HT interact to drive the formation of new associations9-14. However, these hypotheses have not been tested directly because it has not been possible to interrogate and manipulate multiple neuromodulatory systems in a single subject. Here, we establish a mouse model enabling simultaneous genetic access to the brain's DA and 5HT neurons. Anterograde tracing revealed the nucleus accumbens (NAc) to be a putative hotspot for the integration of convergent DA and 5HT signals. Simultaneous recording of DA and 5HT axon activity, together with genetically encoded DA and 5HT sensor recordings, revealed that rewards increase DA signaling and decrease 5HT signaling in the NAc. Optogenetically dampening DA or 5HT reward responses individually produced modest behavioral deficits in an appetitive conditioning task, while blunting both signals together profoundly disrupted learning and reinforcement. Optogenetically reproducing DA and 5HT reward responses together was sufficient to drive acquisition of new associations and supported reinforcement more potently than either manipulation alone. Together, these results demonstrate that striatal DA and 5HT signals shape learning by exerting opponent control of reinforcement.

  View details for DOI 10.1038/s41586-024-08412-x

  View details for PubMedID 39586475

• Feasibility and Methodology of a Pilot Free Blood Pressure Monitoring and Follow-Up Program at Two Free Clinics. Journal of primary care & community health Mikos, G., Yu, B., Balbin, J., Martinez-Reyes, L., Tang, J. M., Lieu, B. N., Tran, E., Xue, A., Lee, J., Wary, N., Franke, C., Panyanouvong, N., Chaclan, M. J., Chang, T. H., Chen, C., Guo, M. Y., Harvell, K., Horan, R., Johnson, N. A., Kim, A., Liu, E., Liu, L., Nuñez-Perez, P., Quig, M., Sanyal, A., Sharma, K., Wang, I., Wang, K., Filsoof, A., Charon, M., Montacute, T., Singh, B. 2024; 15: 21501319241278836

  Abstract

  Hypertension affects approximately 1 in 2 adults in the US. Home blood pressure (BP) monitoring programs are effective in the diagnosis and management of hypertension. Free clinics serve as an integral safety net for millions of uninsured and economically disadvantaged patients in the US. The feasibility and effects of a free home BP monitoring and follow-up program in a free clinic setting is not well characterized.This was a prospective study of the implementation of a pilot BP monitoring and follow-up program between March 2021 and August 2023 at 2 free clinics in the San Francisco Bay Area. A total of 78 hypertensive patients were enrolled in the program and given a free BP monitor. We surveyed via telephone the change in systolic and diastolic BPs and BP monitor use and comfort at 3 weeks. Volunteers in clinic roles involved in the BP monitoring program were surveyed to assess their time spent and perceptions of the program.Of the 78 patients, 37 provided responses to the 3-week survey. A total of 36 of 37 (97%) patients reported using their BP monitor. A total of 35 patients reported using it at least once a week (95%), with the majority reporting at least four uses a week (68%). A total of 36 patients (97%) planned on continuing to use their BP monitor. At 3 weeks, the mean systolic and diastolic BP changed by -6.40 mmHg (95% CI, -10.8 to -2.01 mmHg; P = .00577) and -2.72 mmHg (95% CI, -5.62 to 0.188 mmHg; P = .0657), respectively. The time commitment for this program ranged from 130 ± 51 min for program leaders to 16 ± 14 min per week for patient-facing roles. All volunteer roles (patient-facing, phone follow-up, program leaders) expressed that they had a clear understanding of their responsibilities in the program (median 4 on Likert scale, IQR 3-5).Home BP monitoring and follow-up is feasible to implement in free clinics, resulting in high rates of patient engagement among respondents. Our findings suggest that home BP monitoring and follow-up programs may be beneficial in vulnerable patient populations.

  View details for DOI 10.1177/21501319241278836

  View details for PubMedID 39269685

• Pavement ant extract is a chemotaxis repellent for C. elegans. microPublication biology Lopez, J. S., Ali, S., Asher, M., Benjamin, C. A., Brennan, R. T., Burke, M. L., Civantos, J. M., DeJesus, E. A., Geller, A., Guo, M. Y., Haase Cox, S. K., Johannsen, J. M., Kang, J. S., Konsker, H. B., Liu, B. C., Oakes, K. G., Park, H. I., Perez, D. R., Sajjadian, A. M., Torio Salem, M., Sato, J., Zeng, A. I., Juarez, B. H., Gonzalez, M., Morales, G., Bradon, N., Fiocca, K., Pamplona Barbosa, M. M., O'Connell, L. A. 2024; 2024

  Abstract

  Ant behavior relies on a collection of natural products, from following trail pheromones during foraging to warding off potential predators. How nervous systems sense these compounds to initiate a behavioral response remains unclear. Here, we used Caenorhabditis elegans chemotaxis assays to investigate how ant compounds are detected by heterospecific nervous systems. We found that C. elegans avoid extracts of the pavement ant ( Tetramorium immigrans ) and either osm-9 or tax-4 ion channels are required for this response. These experiments were conducted in an undergraduate laboratory course, demonstrating that new insights into interspecies interactions can be generated through genuine research experiences in a classroom setting.

  View details for DOI 10.17912/micropub.biology.001146

  View details for PubMedID 38596360

  View details for PubMedCentralID PMC11002644