Fig. 7
From: Regulation of density of functional presynaptic terminals by local energy supply
Linear correlations between local energy supply, Ca2+-sensitivity-related proteins in terminals and functional terminal density. (a-d) Co-staining and quantitative analysis of mitochondria, functional terminals and presynaptic proteins. (a) At the low and high [Mg2+]o conditions, mitochondria, functional terminals and Ca2+-sensitivity-related proteins were marked at the same dendritic branch. The numbers 1 and 2 indicated the positions of two nonfunctional terminals marked by white circles. (b) No correlation between normalized quantity (Q) of SYP (Q SYP ) and N mito , whereas linear correlation between total amount of Ca2+-sensitivity-related proteins (ΣQ proteins ) and N mito . (c and d) Relative quantity of Ca2+-sensitivity-related proteins to structure-related protein SYP, i.e. ΣQ proteins /Q SYP , was linearly correlated with N mito (c and d, black circles), meanwhile the density of functional terminals (N 5AP ) was also linearly correlated with N mito (blue diamonds) at the low (c) and high [Mg2+]o conditions (d) (n = 9 AOIs from 1 coverslip for each group, the two coverslips were from the same culturing dish). Each point represented an AOI for (b-d). Pseudo-color scale: fluorescent intensity. (e) The change of ΣQ proteins (ΔΣQ proteins ) was linearly correlated with the change of [ATP]i (Δ[ATP]i) after different treatments. (f) ΔN 5AP and Δ[ATP]i exhibited linear correlation after different treatments. For (e and f), the treatments included adding 50 nM FCCP for 16 hr, reducing Glucose concentration from 28 to 2 mM in culture medium for 12 hr and elevating [Mg2+]o from 0.8 to 1.0 or 1.2 mM for 4 hr (n = 4–6 coverslips for e; n = 5–8 coverslips for f). The percentage in (e and f) was normalized to the mean of Ctrl 0.8 group (0 %). The experiments were performed using sister cultures for each treatment. The mean ± SEM of coverslips was presented. Linear regression for (b-f)