BDNF-TrkB controls cocaine-induced dendritic spines in rodent nucleus accumbens dissociated from increases in addictive behaviors

Ethan M. Anderson, Anne Marie Wissman, Joyce Chemplanikal, Nicole Buzin, Daniel Guzman, Erin B. Larson, Rachael L. Neve, Eric J. Nestler, Christopher W. Cowan, David W. Self

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

Chronic cocaine use is associated with prominent morphological changes in nucleus accumbens shell (NACsh) neurons, including increases in dendritic spine density along with enhanced motivation for cocaine, but a functional relationship between these morphological and behavioral phenomena has not been shown. Here we show that brain-derived neurotrophic factor (BDNF) signaling through tyrosine kinase B (TrkB) receptors in NACsh neurons is necessary for cocaine-induced dendritic spine formation by using either localized TrkB knockout or viral-mediated expression of a dominant negative, kinase-dead TrkB mutant. Interestingly, augmenting wild-type TrkB expression after chronic cocaine self-administration reverses the sustained increase in dendritic spine density, an effect mediated by TrkB signaling pathways that converge on extracellular regulated kinase. Loss of TrkB function after cocaine self-administration, however, leaves spine density intact but markedly enhances the motivation for cocaine, an effect mediated by specific loss of TrkB signaling through phospholipase Cgamma1 (PLCγ1). Conversely, overexpression of PLCγ1 both reduces the motivation for cocaine and reverses dendritic spine density, suggesting a potential target for the treatment of addiction in chronic users. Together, these findings indicate that BDNF-TrkB signaling both mediates and reverses cocaine-induced increases in dendritic spine density in NACsh neurons, and these morphological changes are entirely dissociable from changes in addictive behavior.

Original languageEnglish (US)
Pages (from-to)9469-9474
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume114
Issue number35
DOIs
Publication statusPublished - Aug 29 2017

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Keywords

  • Accumbens shell
  • BDNF-TrkB
  • Cocaine addiction
  • Dendritic spines
  • PLC

ASJC Scopus subject areas

  • General

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