Age-Related Impairment of Ultrasonic Vocalization in Tau.P301L Mice: Possible Implication for Progressive Language Disorders
Figure 2
Altered USV pattern in old Tau.P301L mice.
A – Columns in histograms show Freq(USV) (expressed in kHz) used to produce USV in Tau.P301L (black columns) and FVB/N (white columns) mice at age 4–5 and 8–10 months. Note Freq(USV) was similar in old Tau.P301L and FVB/N mice. B – As in A, but for RangeFreq ( = max Freq(USV)−min Freq(USV), see Fig. 1A2). Note RangeFreq of old Tau.P301L mice was significantly reduced when compared to that of old FVB/N and that of young Tau.P301L mice. C - Columns in histograms show the distribution of totT(USV) (in %) vs. frequency (Freq), expressed in class of 10 kHz from 30 to 80 kHz in young Tau.P301L and FVB/N at age 4–5 months. Note that most USV used high 50–60 kHz frequency but some used low 30–40 kHz frequency in both genotypes. D – As in C, but for 8–10 months old mice. Arrows highlight that old Tau.P301L mice never used the low 30–40 kHz frequency component in their USV whereas old FVB/N mice still used both low and high frequencies. E - Columns in histograms show the occurrence (%) of USV of different complexity level as defined by the number of segments (see tags in Fig. 1A2) within the USV. Complexity ranged from low (1) to high (5). Note the similar distribution of complexity in Tau.P301L and FVB/N young mice. F – As in E but for old mice. Note the increased occurrence of USV of low complexity and the reduced occurrence of USV of higher complexity (>1) in old Tau.P301L mice compared to old FVB/N and young Tau.P301L mice. Complexity of old FVB/N mice did not change when compared to that of young FVB/N mice. * indicates a significant inter-strain difference at a given class of age and $ a significant age-related difference for a given strain; ns, non significant inter-strain difference.