Figure 3

Intracellular resting [Ca ²⁺ ] is normal in the cortical neurons of Mcoln1 ^−/− mice. Frequency distributions of resting intracellular [Ca²⁺] levels in the neuronal cell bodies in the primary somatosensory cortical layer II/III (A) and in the apical dendrites of these neurons in the layer I (B). N.s. – no significant difference in distributions between WT and KO mice; p = 0.49 (cell bodies), p = 0.86 (dendrites); n = 536 dendrites and 1825 neurons from 5 mice (KO), n = 312 dendrites and 888 neurons from 3 mice (WT), assessed using clustered rank-sum test [30]. Maximum intensity Z-projections of representative 75-μm thick multiphoton image stacks demonstrating YC3.60 expression in neuronal cell bodies in layer II/III (C) and in apical dendrites in layer I (D). The projections were pseudocolored based on measured [Ca²⁺] levels. Scale bar = 50 μm (C), 20 μm (D). (E). Representative multiphoton sections from layer II/III of somatosensory cortex of Mcoln1 ^−/− and control mice demonstrating intracellular autofluorescent storage material in the YC3.60-expressing neurons. YC3.60 expression is displayed as the sum of signals in the cyan and yellow channels. Scale bar = 50 μm. (F). Plot of intracellular [Ca²⁺] in the neuronal cell bodies in KO mice versus the amount of autofluorescent cytosolic storage material in the same cells. Solid red line shows linear regression, dotted red line – 95% confidence interval. Correlation coefficient = −0.074, p = 0.04. AU = arbitrary units of fluorescence. n = 1825 neurons in 5 mice.