Our laboratory takes both directed and unbiased approaches to identify the molecular mechanisms that underly neural circuit formation and function. If the question requires it, we will not shy away from developing new tools and techniques.



Mechanisms of signal integration

To form the right connections neurons must navigate long distances, guided by attractive and repulsive signals. These ‘guidance cues’ act like streetlights and street signs, and tell the developing neurons where to go to reach their final destinations. Just like when we are driving our cars, neurons encounter multiple signals along the road. While a number of these neuronal guidance signals have been identified, we still don’t understand how multiple attractive and repulsive cues are interpreted inside the developing neuron. Understanding how these cues are integrated and interpreted inside the cell to trigger a diverse array of developmental events is of critical importance if we are to understand the formation, function and malfunction of the human nervous system. We are investigating how a family of intracellular proteins participates in the establishment of brain circuits. These proteins (Cas family) have the potential to interpret and integrate the multiple signals that neurons receive.

Molecular mechanisms of pruning

The initial assembly of neuronal circuits is carried out by progressive developmental events, like the growth of axons (the main output projection of neurons). During these progressive or circuit-building events, excessive projections, which are unnecessary for the mature circuit, are formed. Subsequently, many brain circuits require refinement of these supernumerary connections via regressive events (e.g. death or devolvement of these byproduct projections) in order to properly function. One such regressive event, axonal pruning, remodels immature pathways by removal of exuberant axonal branches. Disruption of normal pruning events during neural development and circuit maturation has been linked to neurodevelopmental disorders, including autism-spectrum disorders. We are taking a variety of approaches to identify the molecular players critical for axonal pruning.

Targeting reactive astrocytes

Common to virtually all neurodegenerative diseases and brain disorders are changes in a glial cell type in the brain called an astrocyte, which become “reactive”. Astrocytes normally perform critical supportive functions in the brain, but the jury still out on whether reactive astrocytes are beneficial or detrimental for the progression of disease. In collaboration with the Fiacco and Wilson labs we are developing new approaches to study the role of reactive astrocytes during neurological disease.



  • December 15, 2020 - Congratulations to Tyler on his successful thesis defense!

  • July 30, 2020 - Our new preprint on the development of a viral-based approach for cell- and time-specific gene expression (ExBox) is now available at bioRxiv.

  • We are looking for postdocs. See the ad here.

  • August 1, 2019 - The Fiacco, Riccomagno and Wilson Labs are awarded a multi-PI R01 grant from NIDA to investigate the role of reactive astrocytes in different models of chronic inflammation. 

  • June 1, 2019 - The Riccomagno and Fiacco Labs are awarded an R03 grant from NIA to study the role of reactive astrocytes in Alzheimer's disease. 

  • March 11, 2019 - Congratulations to Jason for passing his qualifying exam!

  • March 8, 2019 - The Riccomagno and Fiacco Labs are awarded an R21 grant from NINDS. The goal of the proposal is to develop a combinatorial strategy to selectively manipulate reactive astrocytes in disease.

  • January 25, 2019 - Congratulations to Wenny for passing her qualifying exam!

  • October 11, 2018 - The Riccomagno Lab is awarded a 1-year research grant from the CANCER RESEARCH COORDINATING COMMITTEE.

  • September 22, 2018 - The Riccomagno Lab is awarded an R21 grant from NIMH. The major goal of this project is to understand the role of caspase-dependent refinement during brain development.

  • August 29, 2018 - Congratulations to Tyler for passing his qualifying exam!

  • July 1st, 2018 - The Riccomagno Lab is awarded a Hellman Fellowship. The major goal of the award is to explore the mechanisms that regulate thalamo-cortical axon pruning.

  • June 15, 2018 - The Riccomagno Lab is awarded an R01 grant from NINDS. The major goal of this 5 year project is to determine the role of adhesion signaling during cortical development.

  • Earlier 2018 - Congratulations to Jason and Tyler for publishing their papers in Scientific Reports!



Because Science Is Fun!

Martin Riccomagno

Assistant Professor

Will Agnew-Svoboda

Graduate Student


Tyler Vahedi-Hunter

Graduate Student

Wenny Wong

Graduate Student


Jason Estep 

Graduate Student


Teresa Ubina

Graduate Student

Punit Bhattachan

Postdoctoral Fellow


Camila Alvarez

Lab Assistant

Carly Horn

Lab Manager


Habib Soliman

Undergraduate Student


Natalie Taby

Honor's Undergraduate Student


Yiu-Cheung Wong

Lab Assistant Emeritus


Graduate Students
Tyler Vahedi-Hunter - Lecturer at Cal State Bakersfield
Will Agnew-Svoboda - Research Scientist at Akoya Biosciences

Punit Bhattachan - Postdoctoral fellow at Albert Einstein College of Medicine

Lab assistants
Yiu-Cheung (Eric) Wong - PhD student at Stanford University
Camila Alvarez - PhD student at UC Riverside

Undergraduate Students
Nahal Khalkhali (Honor's) - Master's student at UC Irvine
Srinija Maganti - Postbac student at Dartmouth College

Alexis Marquez - Lab Assistant at UC San Francisco
Kieusa Nguyen - Medical Student at Nova Southeastern University
Alexander Taft - Medical Student
Brian Loui - Medical student at Loma Linda University

Mandeep Chhokar - Postbac student at UC
Lauren Lopez (Honor's) - Medical student at UC Riverside
Jasmine Pacheco - EMT
Jessica Avalos (MarcU)- Dental Student
Jonathan Argame -Master's student at Southern California University of Health Sciences
Anthony  Chen -  Clinical Genetic Molecular Biologist Scientist at Ambry Genetics

Abhinandan Singh Pabla - Medical Student at Stritch School of Medicine




Rutlin, M., Rastelli, D., Kuo, W. T., Estep, J. A., Louis, A., Riccomagno, M. M., Turner, J. R., and Rao, M. (2020) The Villin1 Gene Promoter Drives Cre Recombinase Expression in Extraintestinal Tissues. Cellular and Molecular Gastroenterology and Hepatology 10:864-867. PMC7573669


Vahedi-Hunter, T.A., Estep, J.A., Rosette, K.A., Rutlin, M.L., Wright, K.M., and Riccomagno, M.M. (2018) Cas Adaptor Proteins Coordinate Sensory Axon Fasciculation. Scientific Reports 8:5996. PMC5902548 

Estep, J.A., Wong, W., Wong, Y-C. E., Loui, B. M. and Riccomagno, M.M. (2018) β-Chimaerin regulates cerebellar granule cell development. Scientific Reports 8:680. PMC5766509

Agnew-Svoboda, W., Kolodkin, A.L.*, and Riccomagno, M.M.* (2016) Regressive Phenomena: Refining Connections. D.W. Pfaff, N.D. Volkow (eds.), Neuroscience in the 21st Century. * Authors for correspondence

Riccomagno, M.M. * and Kolodkin, A.L. *(2015) Sculpting Neural Circuits by Axon and Dendrite Pruning. Annual Review of Cell and Developmental Biology. 31: 779-805. * Authors for correspondence


Riccomagno, M.M.*, Sun, L. O.*, Brady, C.M., Alexandropoulos, K., Seo, S., Kurokawa, M., and Kolodkin, A.L. (2014) Cas adaptor proteins organize the Retinal Ganglion Cell Layer downstream of Integrin signaling. Neuron 81:779-786 * Equal contribution

Wang, S-H.J., Celic, I., Choi, S-Y., Riccomagno, M., Wang, Q., Sun, L.O., Mitchell, S., Vasioukhin, V., Huganir, R.L., and Kolodkin, A.L. (2014) Dlg5 Regulates Dendritic Spine Formation and Synaptogenesis by Controlling Subcellular N-cadherin Localization. Journal of Neuroscience  34: 12745-12761


Riccomagno, M.M., Hurtado, A., Wang H., Macopson, J.J, Griner, E.M., Betz, A., Brose, N., Kazanietz, M.G., and Kolodkin, A.L. (2012) The RacGAP β2-Chimaerin Selectively Mediates Axonal Pruning in the Hippocampus. Cell 149: 1594–1606


Pachikara, A., Dolson, D.K., Martinu, L., Riccomagno, M.M., Jeong, Y., and Epstein, D.J.  (2007) Activation of Class I transcription factors by low level Sonic hedgehog signaling is mediated by Gli2-dependent and independent mechanisms.  Developmental Biology 305: 52-62


Torban, E., Wang, H-J., Patenaude, A-M., Riccomagno, M., Daniels, E., Epstein, D., and Gros, P. (2006) Tissue, cellular and sub-cellular localization of the Vangl2 protein during embryonic development: effect of the Lp Mutation. Gene Exp. Patterns 7: 346-354


Riccomagno, M.M., Takada, S., and Epstein, D.J (2005) Wnt dependent regulation of inner ear morphogenesis is balanced by the opposing and supporting roles of Shh. Genes & Dev. 19: 1612-1623


Kleber, M., Lee, H-Y., Wurdak, H., Buchstaller, J., Riccomagno, M.M., Ittner, L.M., Suter, U., Epstein, D.J. and Sommer, L. (2005). Neural Crest Stem Cell Maintenance by Combinatorial Wnt and BMP Signaling. J. Cell. Bio. 169: 309-320


Riccomagno, M.M., Martinu, L., Mulheisen, M., Wu, D.K and Epstein, D.J. (2002) Specification of the mammalian cochlea is dependent on Sonic hedgehog. Genes & Dev. 16: 2365–2378


Paganelli, A., Ocaña, O., Prat, M. I., Franco, P., López, S., Morelli, L., Adamo, A., Riccomagno, M.M., Matsubara, E., Shoji, M., Affranchino, J., Castaño, E. and Carrasco, A. (2001) The Alzheimer-related gene presenilin-1 facilitates sonic hedgehog  signalling in Xenopus primary neurogenesis. Mech. Dev. 107: 119-131


  • linkedin

Your details were sent successfully!