|
|
|
Information |
Cellular
and molecular basis of neural regeneration
Susanna E Blackshaw BSc PhDMuriel Tomlinson Lecturer & Reader in Neurobiology We are interested in regeneration of nerve cells and our aim is to understand the molecular mechanisms by which a nerve cell responds to injury, regrows its processes, and remakes specific contacts to restore function to the nervous system. In order to identify novel genes expressed by regenerating nerve cells, we are using polymerase chain reaction (PCR)-based techniques to construct genetic libraries from small numbers of neurons of known function dissected individually from the leech nervous system. By comparing the genes expressed by an intact neuron with those expressed by the regenerating cell, we are identifying the mRNA that is upregulated after injury. These techniques have allowed us to identify both known and novel genes upregulated by the regenerating nerve cell. The principal reason for choosing to work on the nervous system of the medicinal leech is that this nervous system has a demonstrated capacity for repair. Unlike in mammals, neurons in the CNS of invertebrates like the leech can survive damage, can regrow processes and can remake the specific connections that were lost when the damage occurred. Therefore, the signals exist in this nervous system to ensure appropriate restoration of function. Secondly, because this simpler nervous system contains large, identifiable neurons, single neurons of known function can be removed from the nervous system for the construction of genetic libraries or for cell culture. Our hope is that the discovery and characterisation of relevant genes in a simple system will give insights into regeneration in the more complex mammalian CNS. In order to test the function of the novel genes that we have isolated from identified and regenerating leech nerve cells we are using in situ hybridisation and quantitative PCR to study expression patterns of chosen genes, together with antisense oligonucleotides and RNA interference techniques to manipulate function of chosen genes in neurons maintained in culture. For technical reasons we have used adult leech neurons for the construction of cDNA libraries, but we expect that many of the genes expressed by regenerating nerve cells will also be expressed during development, and we are studying expression patterns of genes in the embryonic leech nerve cord. The single neuron libraries that we have generated provide us with a useful tool to access neuronal genes. We are using these libraries in two ways. In collaboration with Drs Robert Maue and Leslie Henderson at Dartmouth Medical School we are isolating and characterising sodium channel genes in identified and regenerating neurons. Secondly in collaboration with colleagues at Berkeley, San Diego, Mexico City and Buenos Aires we are identifying genes expressed selectively in serotonergic neurons and in their embryonic precursor cells. Current Funding: Wellcome Trust, Medical Research Council, Human Frontiers Science Program, EP Abraham Cephalosporin Fund. Other Activities: Fellow, St. Hilda's College; Director, Jacqueline du Pré Music Building, St. Hilda's College.
Terminal bulbs on a Retzius neuron regenerating in a 3D collagen culture. |
||
lwebmaster@anat.ox.ac.uk © 02006 Dept Physiology Anatomy and Genetics |
