» Articles » PMID: 39402674

Cofilin Linked to GluN2B Subunits of NMDA Receptors is Required for Behavioral Sensitization by Changing the Dendritic Spines of Neurons in the Caudate and Putamen After Repeated Nicotine Exposure

Overview
Publisher Biomed Central
Date 2024 Oct 14
PMID 39402674
Authors
Affiliations
Soon will be listed here.
Abstract

Background: Nicotine dependence is associated with glutamatergic neurotransmission in the caudate and putamen (CPu) of the forebrain which includes alterations in the structure of dendritic spines at glutamate synapses. These changes after nicotine exposure can lead to the development of habitual behaviors such as smoking. The present study investigated the hypothesis that cofilin, an actin-binding protein that is linked to the GluN2B subunits of N-methyl-D-aspartate (NMDA) receptors regulates the morphology of dendritic spines in the neurons of the CPu after repeated exposure to nicotine.

Results: Adult male rats received subcutaneous injections of nicotine (0.3 mg/kg/day) or vehicle for seven consecutive days. DiI staining was conducted to observe changes in dendritic spine morphology. Repeated subcutaneous injections of nicotine decreased the phosphorylation of cofilin while increasing the formation of thin spines and filopodia in the dendrites of medium spiny neurons (MSN) in the CPu of rats. Bilateral intra-CPu infusion of the cofilin inhibitor, cytochalasin D (12.5 µg/µL/side), restored the thin spines and filopodia from mushroom types after repeated exposure to nicotine. Similar results were obtained from the bilateral intra-CPu infusion of the selective GluN2B subunit antagonist, Ro 25-6981 (4 µM/µL/side). Bilateral intra-CPu infusion of cytochalasin D that interferes with the actin-cofilin interaction attenuated the repeated nicotine-induced increase in locomotor sensitization in rats.

Conclusions: These findings suggest that active cofilin alters the structure of spine heads from mushroom to thin spine/filopodia by potentiating actin turnover, contributing to behavioral sensitization after nicotine exposure.

References
1.
Stein I, Park D, Flores J, Jahncke J, Zito K . Molecular Mechanisms of Non-ionotropic NMDA Receptor Signaling in Dendritic Spine Shrinkage. J Neurosci. 2020; 40(19):3741-3750. PMC: 7204083. DOI: 10.1523/JNEUROSCI.0046-20.2020. View

2.
Robinson T, Kolb B . Alterations in the morphology of dendrites and dendritic spines in the nucleus accumbens and prefrontal cortex following repeated treatment with amphetamine or cocaine. Eur J Neurosci. 1999; 11(5):1598-604. DOI: 10.1046/j.1460-9568.1999.00576.x. View

3.
Brown R, Kolb B . Nicotine sensitization increases dendritic length and spine density in the nucleus accumbens and cingulate cortex. Brain Res. 2001; 899(1-2):94-100. DOI: 10.1016/s0006-8993(01)02201-6. View

4.
Kim S, Sohn S, Ryu I, Yang J, Kim O, Kim J . Nicotine Rather Than Non-Nicotine Substances in 3R4F WCSC Increases Behavioral Sensitization and Drug-Taking Behavior in Rats. Nicotine Tob Res. 2022; 24(8):1201-1207. DOI: 10.1093/ntr/ntac063. View

5.
Changeux J . Nicotine addiction and nicotinic receptors: lessons from genetically modified mice. Nat Rev Neurosci. 2010; 11(6):389-401. DOI: 10.1038/nrn2849. View