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Adolescent nicotine-induced dendrite remodeling in the nucleus accumbens is rapid, persistent, and D1-dopamine receptor dependent
- Source :
- Brain structurefunction. 221(1)
- Publication Year :
- 2014
-
Abstract
- Chronic nicotine exposure during adolescence induces dendritic remodeling of medium spiny neurons (MSNs) in the nucleus accumbens (NAcc) shell. While nicotine-induced dendritic remodeling has frequently been described as persistent, the trajectory of dendrite remodeling is unknown. Specifically, no study to date has characterized the structural plasticity of dendrites in the NAcc immediately following chronic nicotine, leaving open the possibility that dendrite remodeling emerges gradually over time. Further, the neuropharmacological mechanisms through which nicotine induces dendrite remodeling are not well understood. To address these questions, rats were co-administered chronic nicotine (0.5 mg/kg) and the D1-dopamine receptor (D1DR) antagonist SCH-23390 (0.05 mg/kg) subcutaneously every other day during adolescence. Brains were then processed for Golgi–Cox staining either 1 day or 21 days following drug exposure and dendrites from MSNs in the NAcc shell digitally reconstructed in 3D. Spine density was also measured at both time points. Our morphometric results show (1) the formation of new dendritic branches and spines 1 day following nicotine exposure, (2) new dendritic branches, but not spine density, remains relatively stable for at least 21 days, (3) the co-administration of SCH-23390 completely blocked nicotine-induced dendritic remodeling of MSNs at both early and late time points, suggesting the formation of new dendritic branches in response to nicotine is D1DR-dependent, and (4) SCH-23390 failed to block nicotine-induced increases in spine density. Overall this study provides new insight into how nicotine influences the normal trajectory of adolescent brain development and demonstrates a persistent form of nicotine-induced neuroplasticity in the NAcc shell that develops rapidly and is D1DR dependent.
- Subjects :
- 0301 basic medicine
Male
Nicotine
Histology
Dendritic spine
Dendrite
Nucleus accumbens
Medium spiny neuron
Nucleus Accumbens
Rats, Sprague-Dawley
03 medical and health sciences
0302 clinical medicine
Dopamine receptor D1
Neuroplasticity
medicine
Animals
Neuronal Plasticity
Chemistry
General Neuroscience
Receptors, Dopamine D1
Dendrites
Benzazepines
Rats
030104 developmental biology
medicine.anatomical_structure
Dopamine receptor
Anatomy
Neuroscience
030217 neurology & neurosurgery
medicine.drug
Subjects
Details
- ISSN :
- 18632661
- Volume :
- 221
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Brain structurefunction
- Accession number :
- edsair.doi.dedup.....aa95c75a8c59fe7d3e6f74539019e7c5