Dr Jimena Berni
The development of behaviour
All animals, including ourselves, perform a variety of behaviours with different parts of our bodies. For example we breathe, we swallow and we walk. These behaviours are generated by distinct neuronal circuits located along the nervous system.
Understanding the way in which genes regulate the development of the different neural networks that will ultimately produce timely and adequate behaviours is not a simple or straightforward task, but it is an unsolved, fundamental question that lies at the heart of our understanding of how the central nervous system works. This is what my lab investigates.
We use the fruit fly Drosophila because developmental mechanisms are conserved among different animals and because Drosophila is excellent for genetic and cellular manipulations. We develop and apply the best methods required to answer our specific biological questions (e.g. calcium imaging, expansion microscopy, frustrated total internal reflection method for behaviour, etc…).
We approach the development of behaviour from two complementary points of view:
1) Hox genes and the diversification of circuits
The ectopic expression of the ubx Hox genes in a domain of the fly’s thorax generates a new pair of wings. This remarkable transformative property of Hox genes demonstrates that are key regulators of cellular identity and it has been shown that this is true along the anteroposterior body axis. However, the link between Hox-mediated neuronal diversification and the formation of locally, specialized circuits in the nervous system is far from understood.
The project will shed light on the mechanism and processes that generate the regional specialization of structure and function in the central nervous system. The basic nature of this question strongly suggests that the findings will have implications for understanding the genetic control of neuronal circuitry in many nervous systems including our own.
2) Neuronal mechanism generating exploratory behaviour
At the end of embryogenesis, Drosophila larvae efficiently explore their environment in search for food, alternating straight crawls and turns. This exploration does not require the activity of the brain, it is generated by circuits in the larva’s “spinal cord”. Crawls are generated by activity in abdominal circuits and turns require the asymmetrical activity of the thoracic segments. Finding food, and therefore survival, depends on achieving the correct exploration strategy. This strategy relies on the dynamics of alternation between straight crawls and turns and we still do not understand how these rhythms are generated by the nervous system.
The project will investigate what neurons are involved in the generation of crawls and turns and the cellular mechanism controlling the dynamics of the alternation between the two patterns of movement. The findings will have profound implication in our understanding of animals exploration and dispersion.
This project is co-supervised by Professor Jeremy Niven.
Key references
- D.W. Sims, N.E. Humphries, N. Hu, V. medan, J. Berni. Optimal searching behaviour generated intrinsically by the central pattern generator for locomotion. eLife 2019;8:e50316. 10.7554/eLife.50316*
- Picao-Osorio J, Johnston J, Landgraf M, Berni J, Alonso CR. MicroRNA-encoded behavior in Drosophila. Science. 350(6262), 815-20 (2015) 10.1126/science.aad0217
- Berni J. Genetic dissection of a regionally differentiated network for exploratory behavior in Drosophila larvae. Current Biology 25(10), 1319-26 (2015) 10.1016/j.cub.2015.03.023
- J. Gjorgjieva, J. Berni, J.F. Evers, S. Eglen. Neural Circuits for Peristaltic Wave Propagation in Crawling Drosophila Larvae: Analysis and Modeling. Frontiers in Computational Neuroscience 7,1-19 (2013) 10.3389/fncom.2013.00024
- Berni J*, Pulver SR, Griffith LC and Bate M. Autonomous circuit for substrate exploration in freely moving Drosophila larva. Current Biology 22, 1861-1870 (2012) 10.1016/j.cub.2012.07.048
- Pulver SR, Bayley TG, Taylor AL, Berni J, Bate M, Hedwig B. Imaging fictive locomotor patterns in larval Drosophila. Journal of Neurophysioly 114(5), 2564-77 (2015), 10.1152/jn.00731.2015
Visit Jimena Berni's profile pages for a full list of publications.