September 2019 - 2021. Postdoctoral scholar at Dr. Rebecca Calisi Rodríguez lab (B3 lab) My work in the B3 lab was focused 50% on neuroscience and 50% on science communication. Research My research was focused on the characterization of the effects of single parenting on the amygdala, emotional center of the brain, in the offspring.
SciComm I led the development and directed the Science Communication training program for faculty at UC Davis. This work was in collaboration with the University of California San Diego Research Communications Program and the UC Davis Office of Strategic Communications.
January 2017- September 2019. Postdoctoral scholar at Dr. Megan Dennis lab My research in the Dennis lab was focused on using zebrafish as a model to identify and characterize genetic mutations that lead to epilepsy and or autism spectrum disorder. There I successfully created zebrafish mutants for several genes including the large amino acid transporter LAT1 gene, slc7a5, and the SynGAP1 gene, synngap1b.
Together with the zebrafish team I characterized these two genes genetically, morphologically and behaviorally in stable lines. In addition, we identified/developed a higher-throughput approach to maximize the use of individual zebrafish larvae for these measurements.
Manuscript related to my postdoc at the Dennis lab 1. Assessment of autism zebrafish mutant models using a high-throughput larval phenotyping platform. A. Colón-Rodríguez, J. M. Uribe-Salazar, K.C. B. Weyenberg, A. Sriram, A. Quezada, G. Kaya, E. Jao, B. Radke, P. J. Lein, M. Y. Dennis. In press,November 2020. Ph.D. Research Focus
My research as a graduate student was focused on understanding the mechanism of toxicity of an environmental neurotoxicant, methylmercury (MeHg), on spinal cord motor neurons.
Why? Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease in humans. It is characterized by the degeneration of upper and lower motor neurons, leading to death approximately five years after being diagnosed. There are two forms of ALS: familial (FALS) which accounts for 10% of all ALS cases and sporadic (SALS) which comprises 90% of all ALS cases. In both FALS and SALS the clinical and pathological manifestations are the same [1]. Genetic and environmental factors are considered possible contributors to the development of both forms [2,3]. One environmental toxicant that has been considered a possible contributor to the development of ALS is methylmercury (MeHg) [2-4].
MeHg is a persistent environmental neurotoxicant to which humans are exposed mainly through the consumption of seafood. Motor neurons are one of the targets of MeHg toxicity and exposure to mercury compounds has been reported to lead to ALS-like syndromes [2,4]. In a study using the ALS mouse model SOD1-G93A, exposure to MeHg led to early onset of ALS-like phenotype, presenting a possible gene environment interaction [5]. One of the factors contributing to MeHg-induced motor neuron degeneration is alterations in intracellular calcium [5]. These effects have not been well characterized and were the focus of my dissertation project. The main findings of my dissertation work are that toxicologically relevant MeHg exposure leads to 1) a concentration-dependent cell death of motor neurons, 2) concentration-dependent increases in calcium in motor neurons and 3) that the excitatory ionotropic receptor AMPA mediates the increases in intracellular calcium in motor neurons. The findings of my work contribute to 1) the understanding of MeHg-induced toxicity in motor neurons, 2) provide a platform for ongoing studies focused on identifying the underlying mechanisms by which MeHg is contributing to the accelerated onset of ALS-like phenotype in the SOD1-G93A mouse.
References: 1. Cleveland, D. W. & Rothstein, J. D. From Charcot to Lou Gehrig: deciphering selective motor neuron death in ALS. Nat. Rev. Neurosci. 2, 806–19 (2001). 2. Johnson, F. O. & Atchison, W. D. The role of environmental mercury, lead and pesticide exposure in development of amyotrophic lateral sclerosis. Neurotoxicology 30, 761–5 (2009). 3. Trojsi, F., Monsurrò, M. R. & Tedeschi, G. Exposure to environmental toxicants and pathogenesis of amyotrophic lateral sclerosis: state of the art and research perspectives. Int. J. Mol. Sci. 14, 15286–311 (2013). 4. Praline, J. et al. ALS and mercury intoxication: a relationship? Clin. Neurol. Neurosurg. 109, 880–3 (2007). 5. Johnson, F. O. et al. Exposure to an environmental neurotoxicant hastens the onset of amyotrophic lateral sclerosis-like phenotype in human Cu2+/Zn2+ superoxide dismutase 1 G93A mice : J. Pharmacol. Exp. Ther. 338, 518–527 (2011).
Manuscripts related to my PhD research 1. Effects of methylmercury on spinal cord afferents and efferents – A review. A. Colón-Rodríguez, H. E. Hannon, and W. D. Atchison. Neurotoxicology. In press, December 2016.
2. Evaluating a gene-environment interaction in amyotrophic lateral sclerosis: Methylmercury exposure and mutated SOD1. J. M. Bailey, A. Colón-Rodríguez, and W. D. Atchison. Current Environmental Health Reports. In press, April 2017.
3. AMPA receptor contribution to methylmercury-mediated alteration of intracellular Ca2+ concentration in human induced pluripotent stem cell motor neurons. A. Colón-Rodríguez, N. M. Colón-Carrión, and W. D. Atchison.Neurotoxicology.In press, September 2020.
Awards for research
Best Poster Presentation, UC Davis Human Genomics Symposium, Sacramento, CA, November 2018.
Scholarship to attend the Zebrafish Development and Genetics Course at the Marine Biological Laboratory, Woods Hole, MA, August 2017.
SOT Women in Toxicology Graduate Student Achievement Award, March 2015.
AGEP NSF Scholar Award, February 2015.
MSU Center for Integrative Toxicology NIEHS T32 Fellowship (T32ES007255-26), MI, 2014 - 2016.
SFN Neuroscience Scholars Program Fellow, August 2014- July 2016.
SOT Hispanic Organization of Toxicologists Travel Award for the 2014 Annual SOT Meeting, Phoenix, AZ. March 2014.
SOT Perry J. Gehring Diversity Student Travel Award for the 2013 Annual SOT Meeting, San Antonio, TX. March 2013.
Honorable Mention, SOT Perry J. Gehring Diversity Student Travel Award for the 2011 Annual SOT Meeting, Washington, DC. March 2011.