Daniel Colon-Ramos PhD
Assistant Professor of Cell Biology
Neural connectivity; Brain; Nematode C. elegans
The human brain consists of 100 billion neurons and over 100 trillion synapses. The ability of a neuron to find its correct target in this complex environment is critical for the formation of the circuits that underlie human behavior. How do neurons discriminate between a plethora of target choices to form precise synaptic connections and assemble specific neural circuits?
We have established a system in the C. elegans nerve ring (the nematode brain) to study this question. In C. elegans we can visualize synapse development in vivo with single cell resolution, and use genetic and cell biological tools to dissect the molecular and cellular components required for the development of the nematode brain. Using this system we discovered that glial cells are required for the assembly of behavioral circuits in the brain. To our knowledge this is the first evidence that glial cells can specify precise neural connectivity in vivo.
We also discovered a novel function for the Netrin receptor UNC-40/DCC in directing synaptic targeting. These findings prompt the following questions: How does the Netrin receptor direct synapse formation? How do glial cells orchestrate circuit assembly in the brain? What other molecular signals govern synaptic targeting in the nematode brain? Our lab will couple genetic, molecular and biochemical techniques to identify the signals that direct precise circuit connectivity in the nematode brain.
- Rankin BR, Moneron G, Wurm CA, Nelson JC, Walter A, Schwarzer D, Schroeder J, Colón-Ramos DA, Hell SW. Nanoscopy in a living organism expressing GFP. Biophys J. 2011 Jun 22;100(12):L63-5.
- Ha H., Hendricks M., Shen Y., Gabel C., Fang-Yen C., Qin Y., Colón-Ramos D.A., Shen K., Samuel A., Zhang Y. Distinct neuronal circuits regulate aversive olfactory learning in Caenorhabditis elegans. Neuron. 2010 Dec 22;68(6):1173-86. PMID: 21172617
- Colón-Ramos D.A. (2009) Chapter 2 Synapse Formation in Developing Neural Circuits. Curr Top Dev Biol; 87:53-79
- Colón-Ramos D.A., Shen K. (2008) Cellular conductors: glial cells as guideposts during neural circuit development. PLoS Biol. 6:e112
- Colón-Ramos, D.A., Margeta, M., Shen, K., (2007). Glia promote local synaptogenesis through UNC-6/Netrin signaling in C. elegans. Science. 318 (5847): 103-6.
- Colón-Ramos D.A.*, Shenvi C.L.*, Weitzel, D.H., Gan E.C., Matts R., Cate J. and Kornbluth S., 2006, Direct ribosomal binding by a cellular inhibitor of translation. Nat. Struct. Mol. Biol. Feb; 13 (2): 103-11
- Colón-Ramos D.A., Irusta P., Gan E.C., Olson M.R., Song J., Morimoto R.I., Elliott R.M., Lombard M., Hollingsworth R., Hardwick J.M., Smith G.K., Kornbluth S., 2003, Inhibition of translation and induction of apoptosis by Bunyaviral Non-structural proteins bearing sequence similarity to Reaper. Mol. Biol. Cell Oct; 14 (10) 4162-72
- Colón-Ramos D.A., Salisbury J., Sanders M., Shenoy S., Singer R., García-Blanco M.A., 2003, Asymmetric distribution of nuclear pore complexes and the cytoplasmic localization on b2-tubulin mRNA in Chlamydomonas reinhardtii. Dev. Cell Jun; 4(6):941-52.