Wellcome PhD Students: Final Year Talks
Thursday 25 September
Room 249, 2nd Floor, Medical Sciences Building, Gower Street
12.30pm: Scott Curran
12.55pm: Kristina Tubby
1.20pm: Miguel Tillo
1.45pm: Alex Sinclair-Wilson
2.10pm: Elena Scarpa
Dr Arantza Barrios
University College London
Dept. Cell and Developmental Biology
Rockefeller Building, Room 518
2009-2012- Research Associate at Rutgers University
2005-2009- Postdoctoral fellow at Albert Einstein College of Medicine
2003-2004- Postdoctoral fellow at MRC LMCB
2002 PhD in Developmental Biology- University College London
1996 BSc in Biology – Universitat de Barcelona and King’s College London
Decision-making is NOT an ability exclusive to humans and furry animals. All organisms with a nervous system need to choose amongst their behavioural repertoire the behaviour most appropriate for a specific situation. Failure to do this can lead to death or lack of offspring and therefore, the ability to produce optimal choices is under evolutionary pressure.
My lab uses a genetic model organism with a nervous system of only 383 neurons, the C. elegans male, to provide molecular and cellular resolution to the decision-making process. Studies of decision-making in humans, rodents, flies and worms demonstrate that a similar organisational and molecular logic underlies the neural circuits for behavioural choice in vertebrates and invertebrates. The cellular logic involves the integration of sensory input with internal state and previous experience. The molecular logic involves a modulatory role for neuropeptides.
The nematode C. elegans, with its amenability to genetics, phylogenetic molecular conservation, complete neural connectome, and broad range of tools to optically probe neural circuit function is a powerful system for neuroscience research. To study the cellular and molecular mechanisms of decision-making, my lab exploits an ethologically-relevant behavioural decision of the male: to stay on a source of food to feed or to leave a source of food to explore in search of mates.
To reproduce, the C. elegans male must find a mate. Well-fed, mate-deprived adult males make the risky choice to leave a plentiful source of food to explore their environment in search of mates. In contrast, recent experience with a mate while exposed to food produces a durable behavioural switch that restricts exploration within the limits of the food source. A period of starvation also suppresses mate-searching behaviour in the absence of mates. Thus, the decision to leave or to stay at a source of food requires the male to evaluate the presence or absence of mates, the presence or absence of food and his own physiological state in order to control his exploratory behaviour. The level of nutritional drive, reproductive drive and the probability of finding a mate determine the salience of food and the male’s behavioural response to a food source.
A male alone (left) explores inside and outside the food patch. Right Panel: A male with mates (centre) explores only within the limits of the food patch.
Through a multidisciplinary approach combining genetics, behaviour and optical probing of neural circuits, we aim to unravel the molecular and cellular mechanisms by which the decision to stay or to leave a source of food is executed. Notably, we have found that the molecular pathways that regulate the properties of the C. elegans mate-searching circuit are conserved and have similar functions in humans. These include an insulin-like pathway that signals nutritional status (daf-2) and a secretin-like neuropeptide system (pdf-1/pdfr-1) that signals reproductive drive and generates an internal state of arousal to explore in search of mates.
- Barrios, A. (2014). Exploratory decisions of the C. elegans male: a conflict of two drives. Seminars in Cell and Developmental Biology. 10.1016/j.semcdb.2014.06.003
- Barrios, A.*, Ghosh, R., Fang, C., Emmons, S.W. and Barr, M.M. (2012). PDF-1 neuropeptide signaling modulates a neural circuit for mate-searching behavior in C. elegans. Nature Neuroscience, 15, 1675-7682. * Corresponding author
- Barrios, A.*, Nurrish, S., Emmons, S.W.* (2008). Sensory regulation of C. elegans male mate-searching behaviour. Current Biology 19 (23): 1865-71. * Corresponding author
- Barrios, A., Poole, R., Durbin, L., Brennan, C., Holder, N., Wilson, S.W. (2003). Eph signaling regulates mesenchymal to epithelial transition of the paraxial mesoderm during somite morphogenesis. Current Biology 13 (18): 1571-82.
- Williams, J.A., Barrios, A., Gatchalian, C., Rubin, L., Wilson, S.W., Holder, N. (2000).
- Programmed cell death in zebrafish rohon beard neurons is influenced by TrkC1/NT-3 signalling. Dev Biol. 226(2):220-30.
- Durbin, L., Sordino, P., Barrios, A., Gering, M., Thisse, C., Thisse, B., Brennan, C., Green, A., Wilson, S., Holder, N. (2000). Anteroposterior patterning is required within segments for somite boundary formation in developing zebrafish. Development 127(8):1703-13.
- Durbin, L., Brennan, C., Shiomi, K., Cooke, J., Barrios, A., Shanmugalingam, S., Guthrie, B., Lindberg, R., Holder, N. (1998). Eph signalling is required for segmentation and differentiation of the somites. Genes Dev 12(19):3096-109.
Page last modified on 28 jul 14 12:32 by Edward D Whitfield