Skip to main content
. 2019 Mar 28;13:119. doi: 10.3389/fncel.2019.00119

Figure 5.

Figure 5

Development of responses to sinusoidal amplitude modulated (SAM) tone bursts. (A) PSTHs of responses to 150 repetitions of SAM stimulation at 50 Hz modulation frequency for BCs (left) and SCs (right) at P12 (top) and P30 (bottom). Note the increased firing rates in both cells types at P30. Right: schematic of a cross-correlation function used to calculate modulation depth (C) and reproducibility (D) between trials. Modulation depth was defined as the SD of the first cycle and the reproducibility as the peak of the normalized cross-correlation. (B) The vector strength (VS) at Fmod = 20 and 50 Hz decreases with maturity for both BCs and SCs (Fmod = 20 Hz; effect of cell type p = 0.91, effect of age p < 0.001, interaction cell type × age p = 0.9; Fmod = 50 Hz; effect of cell type p = 0.93, effect of age p < 0.001, interaction cell type × age p = 0.91; two-way ANOVA), while showing no age-dependence for Fmod = 100–500 Hz (Fmod = 100 Hz: effect of cell type p = 0.9, effect of age p = 0.1, interaction cell type × age p = 0.99; Fmod = 200 Hz: effect of cell type p = 0.57, effect of age p = 0.3, interaction cell type × age p = 0.35; two-way ANOVA). Symbols indicate mean ± SD. For Fmod = 500 Hz, the VS is generally higher in BCs than in SCs (effect of cell type p < 0.001, effect of age p = 0.03, interaction cell type × age p = 0.19; two-way ANOVA). (C) In both cell types, modulation depth at Fmod = 20 and 50 Hz decrease with maturity (Fmod = 20 Hz; effect of cell type p = 0.65, effect of age p < 0.001, interaction cell type × age p = 0.13; Fmod = 50 Hz; effect of cell type p = 0.89, effect of age p < 0.001, interaction cell type × age p = 0.45; two-way ANOVA). There is no age-dependent effect for Fmod 100–500 Hz (Fmod = 100 Hz: effect of cell type p = 0.67, effect of age p = 0.11, interaction cell type × age p = 0.25; Fmod = 200 Hz: effect of cell type p = 0.21, effect of age p = 0.12, interaction cell type × age p = 0.02; two-way ANOVA). Comparison between the cell types shows larger modulation depth in BCs for Fmod = 500 Hz (Fmod = 500 Hz: effect of cell type p < 0.001, effect of age p = 0.03, interaction cell type × age p = 0.05; two-way ANOVA). D, Reproducibility shows similar developmental pattern for BCs and SCs, being reduced with age at Fmod = 20 and 50 Hz (Fmod = 20 Hz; effect of cell type p = 0.44, effect of age p = 0.02, interaction cell type × age p = 0.65; Fmod = 50 Hz; effect of cell type p = 0.88, effect of age p = 0.01, interaction cell type × age p = 0.78; two-way ANOVA), and without changes at Fmod = 100–500 Hz (Fmod = 100 Hz: effect of cell type p = 0.93, effect of age p = 0.59, interaction cell type × age p = 0.58; Fmod = 200 Hz: effect of cell type p = 0.96, effect of age p = 0.46, interaction cell type × age p = 0.13; Fmod = 500 Hz: effect of cell type p = 0.03, effect of age p = 0.83, interaction cell type × age p = 0.1; two-way ANOVA) [*p < 0.05; **p < 0.01; ***p < 0.001].