Math Biology Seminar Abstracts

Wednesday, April 10, 2002 2:00 pm LCB 323

Speaker: Peter Roper (NIH, Bethesda).

Title: ``Modelling opioid-mediated bursting in vasopressin cells, or What goes up must come down''

Abstract: The hormone vasopressin (AVP) controls both the concentration of the blood and the blood pressure. It is released, in response to either dehydration or haemorrhage, from the axonal terminals of secretory neurones. AVP cells in the unstimulated rat fire in a slow, irregular discharge pattern (<10 Hz), however when the animal becomes dehydrated, they discharge lengthy, repeating bursts of spikes. The mechanism underlying the initiation of each burst has recently been clarified experimentally, the burst termination has yet to be determined. We have performed a combined electrical, calcium fluorescence and mathematical modelling investigation; and our work suggests that burst termination must be caused by the progressive desensitization to calcium of a potassium channel. Furthermore, we predict the time course of this desensitization, and we have proposed the opioid dynorphin to be a candidate messenger for the process.

For more information contact J. Keener, 1-6089