Life Lines

Next stop: Iowa. The Iowa Physiological Society, a local chapter of The American Physiological Society, held their 15th annual meeting on Saturday October 9th at Des Moines University.

i-a0dccd48d36342b4ea1a7d24ae4da85c-IowaPS-thumb-300x36-59542.bmp Here are some of the comparative physiology highlights from their annual meeting:

The Lizard “Kiss and Run”: The main method of neurotransmitter release is usually thought to occur by exocytosis where a vesicle, which holds the neurotransmitters, fuses with the plasma membrane of a cell and releases its contents into the fluid outside of the cell. Some vesicles, however, have been described as only temporarily making contact with the plasma membrane to release their contents and then return to their original location within the cell. This process is called “kiss and run”. Researchers Zhang et al., from Grinnell College in Grinnell, IA have been studying this process in lizard neuromuscular junctions (i.e. where the nerve and muscle meet and the nerve can tell the muscle what to do) and how neurotransmitters are released and have found that some vesicles in lizards use this process, whereas others use exocytosis to release their signals.
X. Zhang and C. Lindgren, “Kiss and run id only performed by a specialized sub-pool of synaptic vesicles at lizard neuromuscular junction.

Blood Clot Inhibitor in Wood Turtles: In mammals, blood clotting occurs more slowly as body temperature declines. Researchers from the Department of Biology and the University of Northern Iowa in Cedar Falls have been comparing the process of blood clotting (coagulation) in wood turtles that are hibernating to those that are not. When they added turtle plasma to human plasma, the clotting time of the human plasma increased indicating that a clotting inhibitor is present in the turtle plasma.
N Yadav, J Tamplin and DK Saunders, Comparison of blood coagulation factors and inhibitors between hibernating and nonhibernating wood turtles (Glyptemys insculpta).

Changes in the Brains of Breeding Zebra Finches: Researchers Dr. Christensen from Drake University in Des Moines and Dr. Vleck from Iowa State University in Ames have been studying hormonal changes that occur in the brains of zebra finches following breeding. What they have found is that the anterior pituitary of birds with prior breeding experience contains both glycated and nonglycated forms of prolactin compared to birds without prior experience who only carried the nonglycosylated form.
D. Christensen and CM Vleck. Effects of breeding status and experience on prolactin isoforms in the anterior pituitary of a passerine.

To read more about the comparative and regular physiology highlights from the meeting, click here.