Correlation of BF lactate release with waking theta. Lactate responses (percentage of pretreatment level; y-axis) in individual samples collected during the SD day (pretreatment and treatment periods; on average, 6 lactate samples were contributed by 1 rat) were matched with corresponding waking theta responses (high-to-low waking theta ratio; percentage difference; x-axis) of the 30 min collection period and plotted separately for each age group: Y (•), M (×), O (○) (nY = 10; nM = 5; nO = 13). Simple regression line is shown for each plot. Statistically significant positive correlation (p < 0.005; Pearson's product moment correlation) was found in the young but not in the middle-aged or old group.
