This proposal aims to understand the cellular mechanisms by which sex stero d hormones (androgens, estrogens) alter the waveshape of spikes generated by the electric organ in a species of fish with a sexually dimorphic electric organ discharge. The 7 sections described herein can be summarized as an attempt to describe the action of steroid hormones on the biophysical properties, specifically ion conductances, of this tissue. In addition, these cells will be analyzed morphologically to determine the extent of synaptic and spiking membrane as this will aid in the interpretation of the biophysical data. Also, a medullary nucleus, called the pacemaker nucleus, which drives the electric organ, will be investigated in terms of its potential role in influencing spike waveshape in the electric organ. The significance of this study is two fold. First, by understanding how steroid hormones alter the ion conductances of excitable cells, this work will fill in the """"""""black-box"""""""" between sex steroids and behavior. It is know where sex steroids bind in the brain and that they may alter neural activit , but their mechanisms re unknown. Thus, this may be a benefit to an understanding of hormonal modulation of behavior and, perhaps, sexual dysfunction. The other, more general, point is that this work will illuminate the fundamental question of how excitability of an excitable membrane may be regulated.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
1R01NS025513-01A1
Application #
3410727
Study Section
Communication Sciences and Disorders (CMS)
Project Start
1989-08-01
Project End
1992-07-31
Budget Start
1989-08-01
Budget End
1990-07-31
Support Year
1
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of Texas Austin
Department
Type
Schools of Arts and Sciences
DUNS #
City
Austin
State
TX
Country
United States
Zip Code
78713
Zakon, Harold H (2012) Adaptive evolution of voltage-gated sodium channels: the first 800 million years. Proc Natl Acad Sci U S A 109 Suppl 1:10619-25
Markham, Michael R; McAnelly, M Lynne; Stoddard, Philip K et al. (2009) Circadian and social cues regulate ion channel trafficking. PLoS Biol 7:e1000203
Liu, He; Wu, Ming-ming; Zakon, Harold H (2008) A novel Na+ channel splice form contributes to the regulation of an androgen-dependent social signal. J Neurosci 28:9173-82
McAnelly, M Lynne; Zakon, Harold H (2007) Androgen modulates the kinetics of the delayed rectifying K+ current in the electric organ of a weakly electric fish. Dev Neurobiol 67:1589-97
Liu, He; Wu, Ming-Ming; Zakon, Harold H (2007) Individual variation and hormonal modulation of a sodium channel beta subunit in the electric organ correlate with variation in a social signal. Dev Neurobiol 67:1289-304
Few, W Preston; Zakon, Harold H (2007) Sex differences in and hormonal regulation of Kv1 potassium channel gene expression in the electric organ: molecular control of a social signal. Dev Neurobiol 67:535-49
Stoddard, Philip K; Zakon, Harold H; Markham, Michael R et al. (2006) Regulation and modulation of electric waveforms in gymnotiform electric fish. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 192:613-24
Zakon, Harold H; Lu, Ying; Zwickl, Derrick J et al. (2006) Sodium channel genes and the evolution of diversity in communication signals of electric fishes: convergent molecular evolution. Proc Natl Acad Sci U S A 103:3675-80
Novak, Alicia E; Jost, Manda C; Lu, Ying et al. (2006) Gene duplications and evolution of vertebrate voltage-gated sodium channels. J Mol Evol 63:208-21
Bass, Andrew H; Zakon, Harold H (2005) Sonic and electric fish: at the crossroads of neuroethology and behavioral neuroendocrinology. Horm Behav 48:360-72

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