Figure 1
Diazepam induces significantly different changes on the cortical activity spectral profile of control and Ts65Dn mice. (a) Freely moving mice implanted with EEG electrodes were connected through a cable to the recording unit. The experiment consisted of a 30-min baseline recording, followed by a 90-min post-dosing recording, in which mice were acutely treated with 1, 3, or 10 mg/kg diazepam (i.p.). (b–d) Grouped scatter plots of the first two canonical variables for all mice analyzed are shown in (b–d) for 1-, 3-, and 10-mg/kg doses of diazepam, respectively. Colored points represent mice and are labelled by cluster group. (e) Can1 discriminated the control mice group from the Ts65Dn mice group at 1-, 3-, and 10-mg/kg doses. (f) Can2 differentiated control and Ts65Dn mice groups at 1- and 3-mg/kg doses. (g) The centroid of control mice group treated with 10 mg/kg diazepam was at the highest level of the dendrogram’s hierarchical tree, whereas the centroids of Ts65Dn mice groups treated with 3- and 10-mg/kg doses had the shortest distance among all centroids. (h–j) PSD obtained from baseline and post-dosing recordings were compared for each dose in each genotype (black asterisks in upper and middle panels represent frequency bins in which significant differences in EEG spectral power were observed between baseline and treatment conditions; relative changes are expressed as the log2 of the treatment/baseline ratio). Normalized PSD of control and Ts65Dn mice for each experimental condition was also compared (lower panels). Number of mice: Ct (N = 6) and Ts (N = 7) for all experimental conditions. In (e, f), data represent mean ± SEM and statistical significance is expressed as ** and *** for P < 0.01 and P < 0.001, respectively. In (h–j), solid lines represent means and dashed lines represent SEM and black asterisks indicate statistical significance (P < 0.05).
