Acetaldehyde modulates dendritic spines in the Nucleus Accumbens after chronic treatment

Fois G;Muggironi G;Mulas G;Peana AT;SPIGA, SATURNINO;Diana M.

2013-01-01

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Abstract

Acetaldehyde (ACD), the first metabolite of ethanol (EtOH), appears to be involved in many EtOH psychoactive effects including activation of VTA dopamine (DA) neurons (Foddai et al., 2004; Melis et al., 2007) and motivational properties (Peana et al., 2008; 2010). The aim of this study was to investigate possible ACD-induced changes in dendritic spines of medium spiny neurons (MSN) of the Nucleus Accumbens shell (Naccs). ACD was chronically administered to rats in a modified liquid diet for a total of 21 days. Rats were divided into two groups: 1) liquid diet without ACD; 2) liquid diet with ACD (0,15 %). Rats belonging to group 2 were further divided into 2 subgroups: a) sacrificed, without ACD suspension; b) sacrificed 12 hours after ACD suspension. Subjects were then prepared for histology, utilizing a new method to visualize in the same slice spine’s morphology, TH-positive fibers and PSD-95 positive. Confocal analysis reveals a loss of dendritic spines in MSN (37%), accompanied by a reduction of TH-positive terminals (73 %) and PSD-95 positive elements (68,5%). Further analysis indicates that mature spines as long-thin are selectively affected. These changes occur only in the group b. The reduction of TH-positive terminals, PSD-95 and long-thin spines suggests a profound architectural remodeling of the accumbal synaptic triad. These results indicate functional consequences of these structural modifications and provide further evidence for an active role of ACD in synaptic plasticity in the Naccs.