Effects of fluoxetine on mEPSC frequency in CA3 pyramidal neurons.

<p>A: Exemplary current tracings recorded in the gap-free mode in four representative cells from untreated euploid and Ts65Dn mice and euploid and Ts65Dn mice treated with fluoxetine, showing mEPSC activity. Holding potential was −70 mV. Recordings were made in the presence of 1-µM TTx in the superfusing solution. B: Average frequency-distribution diagrams of mEPSC amplitude for untreated euploid and Ts65Dn mice (B1) and euploid and Ts65Dn mice treated with fluoxetine (B2). Numbers of observations are: 8 (euploid, untreated mice), 4 (Ts65Dn, untreated mice), 7 (euploid, fluoxetine-treated mice), and 5 (Ts65Dn, fluoxetine-treated mice) (these values indicate the number of animals of each group from which recordings were obtained; 2 to 4 cells were recorded from each animal). C: Average, overall mEPSC frequency in the four animal groups (<i>n</i>: as above). One-way ANOVA revealed the existence of a statistically significant difference among groups (<i>p</i> = 0.007). *, <i>p</i><0.05 (Bonferroni post-test; the same test also revealed a significant difference, at the 0.01 level, between Ts65Dn, untreated mice and euploid, fluoxetine-treated mice).