Xenopus Tadpole Research

Outline

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. tadpole swimming

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.

Projects

how simple rules may specify spinal network development. This is the focus of a 3 year BBSRC supported project starting in the spring of 2009.
role of electrical coupling between excitatory reticulospinal neurons controlling swimming
role of lateral-line hair cells in mediating responses to water currents.
Network reconfiguration for struggling
Corelease of excitatory transmitters
Modelling the role of different neuron properties in spinal networks for swimming
how feedback excitation allows prolonged swimming
Roles of inhibitory interneurons and inhibition during swimming and struggling.
Sensory control of tonic inhibitory pathways.
Role of inhibitory brainstem reticulospinal neurons in the control of swimming and function of stopping pathway
Tadpole behaviour, role of pineal eye in control of swimming. Neuroanatomy of central neurons in brain and spinal cord.

Collaborators

Dr Wen-Chang Li, (Royal Society University Research Fellow, School of Biology, University of St Andrews): Physiology and anatomy of CNS neurons.
Prof Roman Borisyuk, (Centre for Theoretical and Computational Neuroscience, University of Plymouth): Modelling developmant of neuronal circuits.
Dr Kate Lewis, (Department of Physiology, Development and Neuroscience, Cambridge University): Molecular marking of spinal cord neurons.
Dr Ervin Wolf, (University of Debrecen, Hungary): Computer modelling.

Postgraduate Opportunities

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

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