| OCR Text |
Show 73 Altered intrinsic calcium activity in LPS-exposed astrocytic somas Somatic calcium events are only rarely observed in acute cortical layer 2/3 slices prepared from healthy animals (Gee et al., 2014; Gee et al., 2015). It has been previously reported that the basal calcium concentration decreases in cultured astrocyte somas, bulk loaded with Fura-2, within the first 24 hr following LPS exposure (Strokin et al., 2011). To the best of our knowledge, the intrinsic event rate has not been measured in astrocytic somas in situ following in vivo LPS-exposure. We imaged cortical layer 2/3 astrocytic somas and, in line with this study, observed a decrease in intrinsic somatic event frequency (Figure 4.3A) which displayed a downward trend at 6 hr (0.10 ± 0.22 events/soma/min; 22/106 somas displayed events) and reached significance by the 24-hr time point (0.04 ± 0.13 events/soma/min; 9/105 somas displayed events) relative to saline-injected controls (0.13 ± 0.30 events/soma/min; 30/136 somas displayed events). We detected differences in the somatic intrinsic event frequency between the groups (p = 0.0079; KW-statistic = 9.69; KW-ANOVA). Specifically, the LPS24 group exhibited a significantly lower somatic intrinsic event frequency than controls (Control vs. LPS6: p > 0.99; Control vs. LPS24: p = 0.01; LPS6 vs. LPS24: p = 0.06, Dunn's post-hoc test). We also measured somatic event characteristics and compared them between the three groups. Although there was a trend towards a progressive decrease in event ΔF/F0 following LPS-injection, no significant differences in intrinsic event ΔF/F0 values (Control: 1.06 ± 0.97; LPS6: 0.76 ± 0.66; LPS24: 0.50 ± 0.10; p = 0.22, KW statistic = 3.03; KW-ANOVA) or in cumulative distribution of event ΔF/F0 values (Control vs. LPS6: p = 0.28, D = 0.24; Control vs. LPS24: p = 0.02, D= 0.51; LPS6 vs. LPS24: p = 0.33, D = 0.34, KS-test) were detected between groups (Figure 4.3B). There was a significant difference detected in the FWHM of intrinsic somatic events between groups (Control: |
