Fig. 1: Weight and CSF dynamics as a function of age.
a Representative images of the six different age groups employed in the study (1, 3, 6, 12, 18, and 24-months (M) old male Wistar rats anesthetized with ketamine/xylazin, n = 6 rats in each age group). b. Body weight of the six different age groups. c Brain weight of the six different age groups. d Relative brain weight of the six different age groups calculated as percentage of body weight. e Brain water content of the six different age groups calculated using the wet-dry technique (note; y-axis does not initiate at 0). f Representative ICP traces obtained in one rat of each age group with the peak indicating injection of 5 µl aCSF to obtain a continuous fluid column. The dashed line indicates the starting point of the last 5 min used to obtain the average ICP in each animal. g Averaged ICP in rats of different ages (n = 6 (1 M, 6 M, 12 M, 24 M) or 7 (3 M, 18 M) rats in each age group). h Representative ICP traces obtained in one rat of each age group undergoing resistance to CSF outflow (Rout) measurements. Arrows indicate initiation of each infusion rate. i Resistance to CSF outflow (Rout) in rats of different ages (n = 6 (1 M, 6 M, 12 M, 24 M) or 7 (3 M, 18 M) rats in each age group). j Representative time course trace of the fluorescence ratio of dextran (outflow/inflow) during ventriculo-cisternal perfusion of one rat (3 M). The squared insert indicates the region used for the quantification of CSF secretion rates. k CSF secretion rates across the six different age groups were quantified from the fluorescence ratio of dextran (n = 6 (1 M, 3 M, 6 M, 12 M, 18 M) or 7 (24 M) rats in each age group. 1 M; turquoise, 3 M; green, 6 M; orange, 12 M; red, 18 M; purple, 24 M; grey. Data are presented as mean ± SEM and statistical significance was tested with one-way ANOVA followed by Tukey’s multiple comparisons test. Asterisks denote statistical significance (*P < 0.05, **P < 0.01, ***P < 0.001). Non-significance is not illustrated for clarity. Source data are provided as a Source Data file and exact P-values in Supplementary Data 2.
