Synaptic Structure and Function in the Mouse Somatosensory Cortex
during Chronic Pain: In Vivo Two-Photon Imaging
Figure 3
Enhanced activation of L2/3 excitatory neurons in response to hind paw stimulation and in response to stimulation of L4 neurons. (a) Identification of the S1 L2/3 excitatory neurons (red dotted circles in the Fura2 image), inhibitory neurons (green, Venus image), and astrocytes (red, SR101 image). Ca2+ indicator (Fura2) was excited at 800 nm two-photon laser, whereas Venus and SR101 were excited at 950 nm laser. Only cells that were positive for Fura2, but not for Venus and SR101, (i.e., excitatory neurons) were included in analysis. Each subpanel shows the same imaging area of the mouse S1 L2/3. (b) Representative traces of Ca2+ transients in identified L2/3 excitatory neurons during the same intensity stimuli (mechanical stimuli of hind paw or electrical stimuli of L4 cells) under control conditions (top traces) and following CFA-induced inflammatory pain (lower traces). (c) Distribution of the amplitude of Ca2+ responses to 10 successive stimuli in a sample of 30 L2/3 excitatory neurons under control conditions (left) and following CFA-induced inflammatory pain (right). (a–c) Reproduced and adapted, with permission, from [13].
