Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


ysu1219192543.pdf (543.91 KB)

ETD Abstract Container

Abstract Header

Substance P Receptor Activation and Desensitization as Monitored By M Current Inhibition

Meadows, Rena Marie
http://rave.ohiolink.edu/etdc/view?acc_num=ysu1219192543

Abstract Details

2008, Master of Science in Biological Sciences, Youngstown State University, Department of Biological Sciences and Chemistry.
Substance P (SP) is a neuropeptide that plays a variety of roles in the human body, including inflammation, nociception, and smooth muscle regulation. In the central and peripheral nervous systems, SP indirectly acts as an excitatory neurotransmitter by inhibiting the M-current, (IM), a time- and voltage-dependent outward potassium current. Activation of IM produces an outward (hyperpolarizing) current which acts to resist neuronal depolarization and action potential production. By inhibiting IM, SP has the ability to modulate neuronal excitability. Since activation of the SP receptor results in IM inhibition, IM amplitude was utilized in the present study as an indirect measure for SP receptor activation and desensitization. Whole-cell voltage-clamp recordings were used to monitor IM in acutely isolated bullfrog sympathetic ganglia neurons. The cell was voltage-clamped at a holding potential of -30 mV, where IM is largely activated. Steps to -60 mV deactivated IM, producing a slow, exponential decrease in current amplitude, followed by an exponential increase in current (reactivation) upon stepping back to -30 mV. Single exponential curve fits were utilized to measure IM amplitude during the reactivation phase. SP application (1 μM) initially produced a rapid and significant inhibition in IM amplitude. However, with continuous SP application, IM amplitude significantly recovered, returning to the control amplitude. This desensitization, defined as a decrease in responsiveness following prolonged or repeated exposure to an agonist, suggests a similar desensitizing loss of functioning by the SP receptor during SP application. The findings presented here support previous studies showing that SP application initially produces inhibition of IM, but continued drug application results in desensitization and loss of IM inhibition.
Mark Womble, PhD (Committee Chair)
Jill Tall, PhD (Committee Member)
Robert Leipheimer, PhD (Committee Member)
53 p.
Biology
Substance P; M Current; Bullfrog Sympathetic Ganglia Neurons

Recommended Citations

Citations

  • Meadows, R. M. (2008). Substance P Receptor Activation and Desensitization as Monitored By M Current Inhibition [Master's thesis, Youngstown State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1219192543

    APA Style (7th edition)

  • Meadows, Rena. Substance P Receptor Activation and Desensitization as Monitored By M Current Inhibition. 2008. Youngstown State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ysu1219192543.

    MLA Style (8th edition)

  • Meadows, Rena. "Substance P Receptor Activation and Desensitization as Monitored By M Current Inhibition." Master's thesis, Youngstown State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1219192543

    Chicago Manual of Style (17th edition)

ysu1219192543
571
© 2008, all rights reserved.
This open access ETD is published by Youngstown State University and OhioLINK.