We use embryos and young tadpoles of the frog Xenopus to ask how nervous systems work at the cellular level, develop to form the correct connections, and are organised to allow animals to behave. Our methods include: analysis of behaviour, whole-cell patch recording, neuron imaging, network modelling. See examples of our projects.
The young Xenopus tadpole provides a very simple model animal with limited behaviour. It can swim either spontaneously or when touched anywhere on the body. A pineal eye detects dimming which speeds up swimming. The tadpole stops swimming when the head bumps into solid objects and the tadpole sticks to things with mucus secreted by a cement gland on the head. If the tadpole is held it can make stronger struggling movements.
This simple behaviour is coordinated by an extremely basic nervous circuit with very few differentiated classes of neuron. For example, at the time of hatching, the spinal cord appears to have only 8 different classes of neuron but the spinal tadpole can still swim. Simple methods for testing the behavioural responses of normal and genetically manipulated tadpoles are given.
As part of this project we have set up a website to explain our work in a way that everyone can understand (tadpoles.org.uk). We are especially keen to inform school children about tadpoles and how they can help us to understand all nervous systems. The website also has a game about tadpoles called Taddypoles (tadpoles.org.uk/games).
We are always looking for potential postgraduate students with an genuine interest in studying how the nervous system of frog tadpoles develops and functions. Contact Dr Steve Soffe or Prof Alan Roberts