1. A single dose of cocaine raises SV2A density in hippocampus of adolescent rats.
- Author
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Rossi R, Bærentzen SL, Thomsen MB, Real CC, Wegener G, Grassi-Oliveira R, Gjedde A, and Landau AM
- Subjects
- Animals, Rats, Amygdala drug effects, Amygdala metabolism, Brain metabolism, Corpus Striatum, Positron-Emission Tomography, Nerve Tissue Proteins drug effects, Nerve Tissue Proteins metabolism, Cocaine metabolism, Cocaine pharmacology, Hippocampus drug effects, Hippocampus metabolism, Membrane Glycoproteins drug effects, Membrane Glycoproteins metabolism
- Abstract
Objective: Cocaine is a highly addictive psychostimulant that affects synaptic activity with structural and functional adaptations of neurons. The transmembrane synaptic vesicle glycoprotein 2A (SV2A) of pre-synaptic vesicles is commonly used to measure synaptic density, as a novel approach to the detection of synaptic changes. We do not know if a single dose of cocaine suffices to affect pre-synaptic SV2A density, especially during adolescence when synapses undergo intense maturation. Here, we explored potential changes of pre-synaptic SV2A density in target brain areas associated with the cocaine-induced boost of dopaminergic neurotransmission, specifically testing if the effects would last after the return of dopamine levels to baseline., Methods: We administered cocaine (20 mg/kg i.p.) or saline to rats in early adolescence, tested their activity levels and removed the brains 1 hour and 7 days after injection. To evaluate immediate and lasting effects, we did autoradiography with [
3 H]UCB-J, a specific tracer for SV2A, in medial prefrontal cortex, striatum, nucleus accumbens, amygdala, and dorsal and ventral areas of hippocampus. We also measured the striatal binding of [3 H]GBR-12935 to test cocaine's occupancy of the dopamine transporter at both times of study., Results: We found a significant increase of [3 H]UCB-J binding in the dorsal and ventral sections of hippocampus 7 days after the cocaine administration compared to saline-injected rats, but no differences 1 hour after the injection. The [3 H]GBR-12935 binding remained unchanged at both times., Conclusion: Cocaine provoked lasting changes of hippocampal synaptic SV2A density after a single exposure during adolescence.- Published
- 2024
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