Email updates

Keep up to date with the latest news and content from BMC Neuroscience and BioMed Central.

This article is part of the supplement: Twentieth Annual Computational Neuroscience Meeting: CNS*2011

Open Access Poster presentation

The role of the large-conductance calcium-dependent potassium channel, BK/Slowpoke, in shaping motor neuron firing during rhythmic activity

Maytee Cruz-Aponte13, Adrian Smith13, Marco A Herrera-Valdez123 and Erin C McKiernan1*

Author Affiliations

1 Mathematical, Computational, and Modeling Sciences Center, Arizona State University, Tempe, AZ 85287, USA

2 School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA

3 School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287, USA

For all author emails, please log on.

BMC Neuroscience 2011, 12(Suppl 1):P217  doi:10.1186/1471-2202-12-S1-P217


The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1471-2202/12/S1/P217


Published:18 July 2011

© 2011 Cruz-Aponte et al; licensee BioMed Central Ltd.

This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Poster presentation

Rhythmic muscle contractions underlie a number of crucial motor behaviors, such as respiration and locomotion. The timing of contractions is determined by the intrinsic activity and synaptic interactions of neurons within what are called central pattern generating (CPG) networks [1,2]. In many systems, motor neurons (MNs) are not part of the classically-defined CPG. However, research suggests that ionic currents in MNs may shape the timing of the final motor output [3,4]. A lot of work has focused particularly on the role of potassium currents in shaping responsiveness and firing of MNs [3,5]. Large-conductance calcium-dependent potassium (BK) currents, encoded by members of the Slowpoke (Slo) gene family, can contribute to action potential repolarization, regulation of firing frequency and interspike interval, repetitive firing, and burst termination [6]. Mutations of Slo genes also lead to a variety of motor disturbances [6]. We developed a biophysical model of bursting activity in MNs to explore the circumstances under which a BK/Slo current expressed in MNs can shape the timing of motor output underlying locomotion. We identify mechanisms by which the BK/Slo current changes the bursting output of MNs, and describe the different behaviors that are observed for varying membrane densities of the underlying channel. We also present preliminary data consisting of electrophysiological recordings from larval Drosophila showing that the changes in motor output predicted by the model are indeed observed when genetic manipulations of Slo channel density (RNA interference constructs) are targeted to MNs [7]. Our results not only further understanding of the specific role of BK/Slo channels in MNs, but contribute more generally to the growing knowledge on the role intrinsic MN properties play in shaping rhythmic motor output.

References

  1. Harris-Warrick RM: Pattern generation.

    Curr. Opinion Neurobiol 1993, 3(6):982-988. Publisher Full Text OpenURL

  2. Marder E, Calabrese RL: Principles of rhythmic motor pattern generation.

    Physiol. Rev 1996, 76:687-717. PubMed Abstract | Publisher Full Text OpenURL

  3. Harris-Warrick RM: Voltage-sensitive ion channels in rhythmic motor systems.

    Curr. Opinion Neurobiol 2002, 12:646-651. Publisher Full Text OpenURL

  4. Heckman CJ, Gorassini MA, Bennett DJ: Persistent inward currents in motoneuron dendrites: Implications for motor output.

    Muscle Nerve 2005, 31:135-156. PubMed Abstract | Publisher Full Text OpenURL

  5. McLarnon JG: Potassium currents in motoneurones.

    Progr. Neurobiol 1995, 47(6):513-531. Publisher Full Text OpenURL

  6. Salkoff L, Butler A, Ferreira G, Santi C, Wei A: High-conductance potassium channels of the SLO family.

    Nature Reviews Neuroscience 2006, 7(12):921-931. PubMed Abstract | Publisher Full Text OpenURL

  7. McKiernan EC: The role of specific voltage-activated and calcium-activated potassium currents in shaping motor neuron firing output during rhythmic motor activity.

    Doctoral Dissertation Physiological Sciences, University of Arizona 2011. OpenURL