Tomás originally graduated from Trinity College Dublin in 2005 with a BA in genetics. He completed his PhD in molecular neuroscience under the supervision of Seth Grant at the University of Cambridge and the Wellcome Trust Sanger Institute in the UK in 2009. His thesis work was supported by a Wellcome Trust PhD Fellowship. Following a year as Junior Research Fellow at Wolfson College, University Cambridge, he relocated to the USA to work as a Postdoctoral Researcher in the group of Susumu Tonegawa (Nobel Laureate, 1987) at Massachusetts Institute of Technology (MIT). At MIT he was centrally involved in the development of novel genetic methods that allow for the labelling and manipulation of specific memory engrams in the rodent brain. This work was supported by Howard Hughes Medical Institute (HHMI) and RIKEN Brain Sciences Institute, Japan. He started his research group in 2017 at Trinity College Dublin, where he is Associate Professor in the School of Biochemistry and Immunology (sub-discipline of Biochemistry) and a Principle Investigator at the Trinity College Institute of Neuroscience. Tomás also holds a joint faculty position at the Florey Institute of Neuroscience and Mental Health at the University of Melbourne, Australia. His research team is supported by the European Research Council (ERC), Science Foundation Ireland (SFI), the Irish Research Council (IRC), the Jacobs Foundation, the Brain & Behavior Research Foundation, the Lister Institute of Preventative Medicine, and the Canadian Institute for Advanced Research (CIFAR).