Computational, Systems and Developmental Neuroscience

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Neural coding in zebrafish tectum

All your thoughts are just patterns of electrical activity in your brain. What is the `neural code' by which these patterns represent information? We are looking at a very simple case: how information about the spatial location of objects in the world is encoded in the optic tectum of the zebrafish. Zebrafish larvae are transparent, therefore we can use genetically-encoded calcium indicators to optically record the activity of many neurons simultaneously while they view simple patterns on a screen. We then investigate how best to decode these patterns using mathematical tools from statistics and information theory. We are also investigating spontaneous activity in the zebrafish, without visual input.

  • Limitations of neural map topography for decoding spatial information. A very common feature of brain wiring is that neighboring points on a sensory surface (eg, the retina) are connected to neighboring points in the brain. It is often assumed that this “topography” of wiring is essential for decoding sensory stimuli. However, in a new paper in the Journal of Neuroscience we showed in the developing zebrafish that topographic decoding performs very poorly compared with methods that do not rely on topography. This suggests that, although wiring topography could provide a starting point for decoding at a very early stage in development, it may be replaced by more accurate methods as the animal gains experience of the world.