ROBERT C. BERDAN

Adjunct Assistant Professor
Department of Cell Biology & Anatomy
Faculty of Medicine
University of Calgary
Calgary, AB T2N 4N1
Owner & operator Science & Art Multimedia
6255-72nd St. N.W.
Calgary, Alberta T3B 3V9
Tel: (403) 247-2457
E-mail: rberdan@scienceandart.org
Websites: www.scienceandart.org
                www.scienceandart.ca

RESEARCH INTERESTS

One of my research goals is to understand the mechanisms underlying neuronal growth following injury in order to identify means by which to enhance nerve regeneration.

A second goal of mine is to understand mechanisms by which synapses are formed during
development and later modulated by electrical activity in the mature nervous system

The physiological mechanisms involved in the induction and regulation of nerve regeneration following injury to the nervous system are complex. Neurons within the central nervous system of mammals generally do not regenerate following injury and are difficult to study. In contrast to vertebrates, some invertebrate species such as the mollusks possess giant central neurons that regenerate rapidly and provide a relatively simple experimental preparation. Many of the physiological processes and molecules that permit molluscan neurons to communicate (e.g. neurotransmitters, neuropeptides and perhaps some nerve growth factors) are identical or homologous to those in vertebrates. I am particularly interested in answering the following questions. What signals associated with nerve injury trigger regeneration? What features of Molluscan central neurons permit them to regenerate quickly. How does spontaneous electrical activity within the nervous system affect neurite outgrowth, formation of new synapses, and the synthesis of nerve growth factors? What is the identity and cellular source of nerve growth factors in the molluscan nervous system. Which genes and gene products are necessary for successful nerve regeneration. Our discovery (Berdan and Ridgway, 1992) that electrical activity in molluscan neurons is necessary for the release of neurite promoting proteins may be relevant to processes involved in learning, memory, and epilepsy in vertebrate neurons. Another discovery we made that injury to a nerve cell results in long term changes in membrane potential and changes in calcium channel expression (Berdan et al., 1993) may be relevant to understanding the mechanisms that trigger growth in an injured neuron.

SIGNIFICANT RESEARCH

Berdan, R.C. and Caveney, S. (1985) Gap junction ultrastructure in three states of conductance. Cell Tiss. Res. 239:111-122.

Berdan, R.C. and Gilula, N.B.G. (1988) The arthropod gap and pseudo-gap junction: Isolation and preliminary biochemical analysis. Cell Tiss. Res. 251:257-274.

Berdan, R.C. and Bulloch, A.G.M (1990) Role of activity in the selection of new electrical synapses between adult Helisoma neurons. Brain Res. 537:241-250.

Berdan, R.C. and Ridgway, R.L. (1992) Release of neurite outgrowth promoting factors by Helisoma central ganglia depends on neural activity. Brain Res. 572:132-138.

Berdan, R.C and Easaw, J. (1992) Modulation of sprouting in organ culture after axotomy of an identified molluscan neuron. J. Neurobiol. 23:433-450.

Bagnall, K.M, Sanders, E.J. and Berdan, R.C. (1992) Communication compartments in the axial mesoderm of the chick. J. Anat. Embryol. 186:195- 204.

Berdan, R.C., Easaw, J. and Wang. R (1993) Alterations in membrane potential following axotomy at different distances from the soma of an identified neuron and the effect of depolarization on neurite outgrowth and calcium channel expression. J. Neurophysiol. 69: 151-164.

Wong, G., Bagnall, K, and Berdan, R.C. (1993) The immediate fate of cells in the epithelial somite of the chick embryo. Anat. Embryol. 188:441-447.

Wang, R., Pang, P.K.T., Wu, L., Karpinski, E., , Shipley, A., Harvey, S. and Berdan, R.C. (1994) Modulation of intracellular calcium in an identified neuron by Parathyroid hormone. Cell Calcium 15:89-98.

Yui, J., Brown, A.J., Berdan, R.C., Tertzak, P., Wegmann, T.G. and Guilbert, L.J. (1994) Purification of human cytotrophoblasts from term by column immuno- elimination. Placenta 15:231-246.

Morrish DW, Dakour J, Li H, Xiao J, Miller R, Sherburne R, Berdan RC, Guilbert LJ. (1997) In vitro cultured human term cytotrophoblast: a model for normal primary epithelial cells demonstrating a spontaneous differentiation programme that requires EGF for extensive development of syncytium. Placenta. 1997 Sep;18(7):577-85.

BOOK CHAPTERS

1. Caveney, S. and Berdan, R.C. (1981) Selectivity in junctional coupling between cells in insect tissues In Insect Ultrastructure (Vol. 2), (ed. H.Akai and R.C. King) Plenum Press, New York, pp. 434-465.

2. Caveney, S., Berdan, R.C., Blennerhassett, M.G. and Sanfranyos, R.G.A.(1986) Cell-to-cell coupling via membrane junctions: Methods that show its regulation by a developmental hormone in an insect epidermis In Techniques in Cell Biology, (Vol. 2.) In Vitro Invertebrate Hormones and Genes (ed. E. Kurstak) Elsevier Scientific Publishers, New York, pp. 1-23.

3. Berdan, R.C. (1987) Intercellular communication in arthropods: Biophysical, ultrastructural and biochemical approaches In Cell-to-Cell Communication (ed. W.C. DeMello) Plenum Press, pp. 299-370.

4. Berdan, R.C., Jones, P. and Bulloch, A.G.M (1988) Modulation of neurite outgrowth: ultrastructure and physiology In Cellular Basis of Neuronal Plasticity. (ed. A.G.M. Bulloch) Manchester University Press pp. 97-128.