Stephen J Eglen

Research interests

My main interests are in the development of the nervous system. I use computational techniques to analyse experimental data and create models of how the nervous system develops. I currently focus on the retina as a model system for understanding neural development. The hope is that principles learnt from the retina will apply to other parts of the nervous system. Some of the topics I study are described below.

Retinotopic map formation

Summary

Neighbouring neurons in the retina project to neighbouring parts of their target (such as the superior colliculus in mouse). The mechanisms underlying the development of these projections have long been debated. There are two major classes of mechanism:

1. molecular gradients (such as those formed by Eph receptors and the correspondding) ephrin ligands.
2. activity-dependent mechanisms whereby neighbouring neurons that fire-together, wire together.

Computational modelling has played an important role in helping understand how these mechanisms can generate ordered neural projections.

Retinal waves

Before the onset of vision, retinal ganglion cells are spontaneously active, producing waves of activity across the retina. Some example movies of these waves are available:

• The Marla Feller et al. (1996) Science paper movies.
• A comparison of experimental and simulated waves to accompany the Marla Feller et al. (1997) Neuron paper.
• Multielectrode array and calcium imaging waves from Annual Reviews in Neuroscience review by Rachel Wong (1999).
• Calcium imaging of ferret retina under control and forskolin from David Stellwagen et. al's 1999 Neuron paper.
• Calcium imaging of developing turtle retina from Evelyne Sernagor's J Neuroscience 2003 paper.
• Multielectrode array recordings from mouse retina in control and dark reared retina's from Jay Demas' J Neuroscience 2003 paper.

Evelyne Sernagor, Matthias Hennig and I currently have a BBSRC grant to develop computational tools for the visualisation and analysis of data recorded from high-density multi-electrode arrays.

Retinal mosaics

The cell bodies of retinal neurons are distributed non-randomly across the retina; such spatial patterns are known as "retinal mosaics" due to the way that the cell bodies, together with their dendrites, tile the retina. I am interested in the developmental mechanisms that drive such spatial patterning.

Here is a fun way of looking at tiling.

The retina

Some useful on-line starting points for looking at the retina are:

• Webvision (USA) or (Spanish mirror). This is a very good overview of the neural organisation of the verterbrate retina. Written by Helga Kolb and colleagues.
• Lance Hahm's Retina reference contain's a wide range of retinal-related information.

Analysis of neurophysiological data

I am one of the named investigators of the CARMEN project. My interest in this project is contributing methods for the analysis of multi-electrode array recordings. Some of this work is in collaboration with the Genes to Cognition project, led by Dr Seth Grant at the Sanger Institute.