Meet the scientists and explore the lab

Bristol University Xenopus Neurobiology

We use very young tadpoles of the South African Clawed toad or frog (Xenopus) to study how  brains work. Our research is supported by grants from the  Biotechnology  and Biological Sciences Research Council  (BBSRC). Previously  the Wellcome Trust supported us. Here are some of the scientists who have worked in our lab recently.

The Laboratory

Bristol University Life Sciences Building

Our laboratory is in the Life Sciences Building up St Michael’s Hill from the centre of Bristol. It was opened by Sir David Attenborough on 6th October 2014.

The Xenopus Tadpole lab is on the ground floor of the shiny, aluminium-clad lab wing (the arrow shows one of our windows).
The central atrium has offices on the right and labs on the left behind all the glass meeting spaces.

Our main lab has places: to raise tadpoles at different temperatures; to make instruments for dissection; to take videos of tadpole behaviour;  to prepare and mount brains on microscope slides; to wash glassware. There are also three stations to record electrical activity in tadpole nervous systems. On the right are doors to smaller rooms used for recording and microscopy.

The Scientists


Four people work routinely in the lab and undergraduate students do projects here during term-time:


The head of the lab is Dr Steve Soffe who is a senior lecturer in Zoology. Here he is using a surgeon’s miscroscope (200x magnification) to place electrodes on the motor nerves in an immobilised tadpole. These record nerve impulses which show when the tadpole is swimming .


Dr Alan Roberts has been working on tadpoles with Dr Soffe since 1979. He is an Emeritus professor which means he works but is not paid! He uses this compound microscope with up to 1000x magnification to see the brain nerve cells filled with dye during electrical recording.


Dr Stella Koutsikou came originally from Greece. Before she came to our lab 2 years ago she worked on how rats respond to sensory stimulation. She is supported by our BBSRC research grant. She makes electrical recordings from nerve cells in the tadpole brain using the microscope (500x) and equipment shown here.


After making recordings she mounts the fixed tadpole brains on a slide. Then we can see the nerve cells which she filled  with dye during recordings.


Mark Olenik  came originally from Kyrgyzstan but his home is now  in Hamburg. He is a post-graduate student supported by the Wellcome Trust . He uses computer models to study how networks of nerve cells allow tadpoles to make rhythmic movements.

During University term time in the winter final year undergraduate students do short research projects in the lab .

The Frogs and tadpoles


The tadpoles we study are produced by  a small colony of adult Xenopus laevis  looked after by the University Animal Services Unit. These are the tanks where the adult toads live in a carefully controlled environment:

Each week mating is induced by injecting a pair of adults with a hormone in late afternoon. If all goes well, the pair are clasped and eggs (about 1 mm across) have been laid by next morning.

Mating Clawed Toads or Frogs with eggs

The female is large and the male clasps her around the waist. He can then fertilise the eggs as they are laid . The eggs  stick to the sides or bottom of the tank.

We collect the eggs and take them to the lab to grow into tadpoles. Find out more by going to the “A Tadpole Laboratory” page.