Periodic Reporting for period 4 - NeuroVisEco (Zebrafish vision in its natural context: from natural scenes through retinal and central processing to behaviour.)
Período documentado: 2020-12-01 hasta 2022-05-31
The importance of this work may be understood from a point of view of “efficient sampling”. Simply put, in nature the physical and chemical information detectable by animal’s senses, (e.g. light, sounds, odorants etc.) differs between different environments that animals live in. For any animal to efficiently use its specific set of senses, it should specifically invest in circuits and mechanisms that are best at picking up and processing the type of information that is likely to occur in their natural world, or that is of particular importance for survival and reproduction. A better understanding of how evolution can balance the specific tuning and complexity of an animal’s sensory complement may lead to the design “smart-sensors” for our own technological applications. Moreover, it will help us understand the fundamental mechanisms and strategies that neuronal networks use to compute information.
Turning to functional recordings in the eye by way of laser-scanning microscopy combined with genetically encoded reporters of neuronal activity, this is exactly what we found. Looking at different sets of nerve cells in the zebrafish eye, in different parts of the retina, we found that the lower eye of larval zebrafish is all but colour-blind, while the upper part of the eye supports rich colour vision. In this work, we also stumbled across another key feature of these animal’s eyes. The part of the retina that looks just above the horizon in front of the fish is extremely UV-light sensitive. Further work revealed that this is probably a specific adaptation of small underwater animals to support prey-capture. While this first part of our project is published (Zimmermann, Nevala, Yoshimatsu et al. 2018), we now follow up on these points using further functional recordings in different populations of neurons both in the retina, and in the brain.