UMMS Affiliation

Department of Psychiatry; Graduate School of Biomedical Sciences, Neuroscience Program; Gene Therapy Center

Date

2-13-2017

Document Type

Article

Disciplines

Molecular and Cellular Neuroscience | Psychiatry | Psychiatry and Psychology

Abstract

Voltage-gated sodium channels are essential for generating the initial rapid depolarization of neuronal membrane potential during action potentials (APs) that enable cell-to-cell communication, the propagation of signals throughout the brain, and the induction of synaptic plasticity. Although all brain neurons express one or several variants coding for the core pore-forming sodium channel alpha subunit, the expression of the beta (beta1-4) auxiliary subunits varies greatly. Of particular interest is the beta4 subunit, encoded by the Scn4b gene, that is highly expressed in dorsal and ventral (i.e., nucleus accumbens - NAc) striata compared to other brain regions, and that endows sodium channels with unique gating properties. However, its role on neuronal activity, synaptic plasticity, and behaviors related to drugs of abuse remains poorly understood. Combining whole-cell patch-clamp recordings with two-photon calcium imaging in Scn4b knockout (KO) and knockdown mice, we found that Scn4b altered the properties of APs in core accumbens medium spiny neurons (MSNs). These alterations are associated with a reduction of the probability of MSNs to evoke spike-timing-dependent long-term depression (tLTD) and a reduced ability of backpropagating APs to evoke dendritic calcium transients. In contrast, long-term potentiation (tLTP) remained unaffected. Interestingly, we also showed that amphetamine-induced locomotor activity was significantly reduced in male Scn4b KO mice compared to wild-type controls. Taken together, these data indicate that the Scn4b subunit selectively controls tLTD by modulating dendritic calcium transients evoked by backpropagating APs.

Rights and Permissions

Copyright © 2017 Ji, Saha, Gao, Lasek, Homanics, Guildford, Tapper and Martin. Citation: Front Cell Neurosci. 2017 Feb 13;11:17. doi: 10.3389/fncel.2017.00017. eCollection 2017. eCollection 2017. Link to article on publisher's site

Comments

Co-author Melissa Guildford Derner is a doctoral student in the Neuroscience Program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.

Related Resources

Link to Article in PubMed

Keywords

nucleus accumbens, spike-timing-dependent plasticity, sodium channel, Scn4b, knockout mice, calcium imaging, dendrites, long-term depression

PubMed ID

28243192

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.