Abstract

A class of zebra fish motility mutants that are motile and can swim but do not respond to touch have been isolated. One of these mutants is termed mao. The phenotype of these mutants suggests that the defect may originate in mechanosensory Rohon-Beard (RB) neurons. Normally, the action potential of RB cells undergoes developmental regulation so that the embryo acquires touch sensitivity. The embryos of mao zebra fish do not acquire such sensitivity. The changes in action potential waveform in RB cells are due to underlying changes in voltage-gated sodium and potassium currents. The RB cells of mao zebra fish have reduced sodium current amplitudes, and action potentials are not generated. In addition, up regulation of sodium current is not observed, even though the normal developmental changes in potassium currents do occur. These data suggest that developmental regulation of RB sodium current may underlie stage-specific acquisition of touch sensitivity. To investigate this possibility, the investigator will examine three specific aims.
The first aim i s to dissect RB whole-cell sodium current into underlying pharmacological and functional components.
The second aim i s to identify the classes of voltage-dependent sodium channel genes expressed in RB cells.
The final aim i s to compare the morphological properties of RB cells in wildtype and mao mutant embryos.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS038937-03
Application #
6540124
Study Section
Special Emphasis Panel (ZRG1-MDCN-3 (01))
Program Officer
Leblanc, Gabrielle G
Project Start
2000-07-01
Project End
2004-04-30
Budget Start
2002-05-01
Budget End
2003-04-30
Support Year
3
Fiscal Year
2002
Total Cost
$300,918
Indirect Cost

  Institution

Name
University of Colorado Denver
Department
Physiology
Type
Schools of Medicine
DUNS #
065391526
City
Aurora
State
CO
Country
United States
Zip Code
80045

  Publications

Carmean, V; Yonkers, M A; Tellez, M B et al. (2015) pigk Mutation underlies macho behavior and affects Rohon-Beard cell excitability. J Neurophysiol 114:1146-57
Carlisle, Tara C; Ribera, Angeles B (2014) Connexin 35b expression in the spinal cord of Danio rerio embryos and larvae. J Comp Neurol 522:861-75
Moreno, Rosa L; Ribera, Angeles B (2014) Spinal neurons require Islet1 for subtype-specific differentiation of electrical excitability. Neural Dev 9:19
McKeown, Kelly Anne; Moreno, Rosa; Hall, Victoria L et al. (2012) Disruption of Eaat2b, a glutamate transporter, results in abnormal motor behaviors in developing zebrafish. Dev Biol 362:162-71
Carmean, Vanessa; Ribera, Angeles B (2010) Genetic Analysis of the Touch Response in Zebrafish (Danio rerio). Int J Comp Psychol 23:91
Wright, Melissa A; Ribera, Angeles B (2010) Brain-derived neurotrophic factor mediates non-cell-autonomous regulation of sensory neuron position and identity. J Neurosci 30:14513-21
Moreno, Rosa L; Ribera, Angeles B (2009) Zebrafish motor neuron subtypes differ electrically prior to axonal outgrowth. J Neurophysiol 102:2477-84
Yonkers, Marc A; Ribera, Angeles B (2009) Molecular components underlying nongenomic thyroid hormone signaling in embryonic zebrafish neurons. Neural Dev 4:20
Fein, Amanda J; Wright, Melissa A; Slat, Emily A et al. (2008) scn1bb, a zebrafish ortholog of SCN1B expressed in excitable and nonexcitable cells, affects motor neuron axon morphology and touch sensitivity. J Neurosci 28:12510-22
Yonkers, Marc A; Ribera, Angeles B (2008) Sensory neuron sodium current requires nongenomic actions of thyroid hormone during development. J Neurophysiol 100:2719-25

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