Skip to main content

Dissecting the retinal inputs to behaviorally relevant computations in the central brain

Final Report Summary - VISUALCIRCUITS (Dissecting the retinal inputs to behaviorally relevant computations in the central brain)

Sensory neurons often display an ordered spatial arrangement that enhances the encoding of specific features on different sides of natural borders in the visual field (for example [1–3]). In central visual areas one prominent natural border is formed by the confluence of information from the two eyes, the monocular-binocular border [4]. Here we investigate whether receptive field properties of neurons in the mouse superior colliculus show any systematic organization about the monocular-binocular border. The superior colliculus is a layered midbrain structure that plays a significant role in the orienting responses of the eye, head and body [5]. Its superficial layers receive direct input from the majority of retinal ganglion cells and are retinotopically organized [6,7]. Using two-photon calcium imaging, we recorded the activity of collicular neurons from the superficial layers of awake mice and determined their direction selectivity, orientation selectivity and retinotopic location. This revealed that nearby direction-selective neurons have a strong tendency to prefer the same motion direction. In retinotopic space, the local preference of direction-selective neurons shows a sharp transition in the preference for nasal versus temporal motion at the monocular-binocular border. The maps representing orientation and direction appear to be independent. These results illustrate the important coherence between the spatial organization of inputs and response properties within the visual system and suggest a re-analysis of the receptive field organization within the superior colliculus from an ecological perspective.
In addition, during the fellowship a number of important training and transfer of knowledge milestones were achieved. Regarding training I was able to attend an excellent leadership course run by the VIB that consisted of two 3 day group workshops plus three individual sessions in the fall of 2017. The focus of this course was to learn about different management techniques focused around how to best supervise PhD students, post-doctoral fellows and the running a laboratory. This has been immensely useful at better supervision of the diverse set of personalities and needs of the different members of the lab.
Transfer of knowledge has mainly be achieved through attending international conferences, but also through teaching at the KU Leuven. Additionally, I have been able to attend some critical expert meeting about the retina, including the European Retina Meetings and FASAB Retinal Biology Meeting,. Attending these meetings has allowed to integrate the laboratories activities into the community and get excellent feedback and training for the lab members. Additionally, the lab has attended to small but more general neural circuits meeting, one at EMBO and the other at CSHL. Attending these meetings has allowed us to learn how our work in the visual system fits into the wider systems neural science community. In addition, it has allowed us to form two formative new collaborations with laboratories in the USA (Hopi Hoekstra at Harvard and Jennifer Hoy at the University of Nevada), which has allowed us to extend the work we do to address questions of evolutionary biology and hunting behaviors. In addition, I have participated in organizing the biannual NERF Symposium of neural technologies.
During the four years of the fellowship the laboratory has grown to include two post-doctoral fellows, four PhD students and a continuous flow of Erasmus and Master’s Thesis students (average 3 at any given time). We have managed to establish the lab in the local community forming 4 productive collaborations with local scientists (Joris de Wit, Lieve Moons, Vincent Bonin and Alan Urban). These collaborations have lead to either a publication together or a grant being awarded. In addition, the fellowship has allowed us to take up rewarding teaching opportunities that have provided access to the excellent student body of the KU Leuven. I’m currently up for renewal of my position both at NERF and the KU Leuven.
For more information please contact Karl Farrow.
Karl Farrow, PhD | Group Leader
NERF - imec, VIB and KU Leuven | Dept. Biology, KU Leuven
NERF - Kapeldreef 75 - B-3001 Leuven - Belgium
Tel: +32 16 28 1827 | Email: karl.farrow@nerf.be
http://www.nerf.be/research/farrow-lab/