Adult-Onset Fluoxetine Treatment Does Not Improve Behavioral Impairments and May Have Adverse Effects on the Ts65Dn Mouse Model of Down Syndrome
Figure 4
Results from stereological assessment of choline acetyltransferase-(ChAT-) positive cells in basal forebrain cholinergic nuclei in Ts65Dn mice and wild-type controls treated either with fluoxetine or vehicle control (2N, vehicle: mice; 2N, fluoxetine: mice; Ts65Dn, vehicle: mice; Ts65Dn, fluoxetine: mice). (a) Stereological counting of choline acetyltransferase-(ChAT-) positive cells in basal forebrain cholinergic nuclei. Shown are representative brain sections from 2N controls and Ts65Dn mice under treatment with vehicle or fluoxetine. Scale bar = 50 μm. The quantification is shown in the bar graph. No differences with regards to cholinergic cell number were detectable between Ts65Dn mice and 2N controls (two-way ANOVA with genotype and treatment as between-subjects factors: genotype effect, F(1,27) = 0.04, ; treatment effect, F(1,27) = 0.61, ; genotype × treatment interaction, F(1,27) = 0.49, ). Graph shows means ± SEM. (b) Cell size of choline acetyltransferase-(ChAT-) positive cells in basal forebrain cholinergic nuclei from Ts65Dn mice and 2N controls. Shown are representative ChAT-stained neurons from euploid mice treated with vehicle or fluoxetine and Ts65Dn mice treated with vehicle or fluoxetine. The bar graph is depicting cell size distributions of ChAT-immunoreactive cells. Cholinergic neurons of euploid mice appeared to be larger than in Ts65Dn mice although the statistical comparison was not significant (two-way ANOVA with genotype and treatment as between-subjects factors: genotype effect, F(1,27) = 2.2, ). Fluoxetine treatment had no significant effect on cell size, although there was a trend towards increasing cell size in Ts65Dn mice (two-way ANOVA with genotype and treatment as between-subjects factors: treatment effect, F(1,27) = 3.08, ; genotype × treatment interaction, F(1,27) = 3.14, ). The graph shows means ± SEM.
