Figure 5.

Effects of modulating extracellular calcium on SyGCaMP2 responses in young and aged mice. (a) The baseline SyG:mCherry ratio in a slice from an aged mouse was measured in aCSF containing 2.5 mM extracellular calcium and in modified solutions containing 1 and 3.5 mM calcium. Responses to 20 stimuli at 20Hz are shown under each condition on the right. (b) The effects of stimulus intensity on SyGCaMP2 responses were measured in <6‐month‐old and >18‐month‐old slices in normal, low and high calcium solutions. Pooled data from 6 separate young (left) and aged slices are shown in panel (c) Data were normalized to the peak response measured in 3.5 mM calcium. Raising calcium had a significantly smaller effect on aged slices than on younger slices