Skip to main content
. 2020 Oct 12;130(11):6005–6020. doi: 10.1172/JCI134793

Figure 2. Decreases in neuronal intrinsic excitability and excitatory currents 48 hours after CCI.

Figure 2

(A) Schematic shows in vivo whole-cell recording methods, and parameters used to characterize the intrinsic properties of the neuronal soma. Changes in intrinsic membrane properties are known to modify the response property of a cell. (B) No difference in RMP was detected between sham and CCI treatment groups (P > 0.05, 2-sided, unpaired t test; n = 9–10 neurons, n = 6–10 mice per group). (C) Box-and-whisker plot showing increased membrane capacitance in neurons of CCI-treated mice (*P = 0.01, unpaired t test; n = 14–15 neurons, n = 10–12 mice per group). (D) After CCI, the mean Rin of layer 2/3 pyramidal cells was significantly decreased (**P = 0.007, Mann-Whitney U test; n = 14–15 neurons, n = 10–12 mice per group). (E) Typical whole-cell recordings from pyramidal neurons showing AP firing at 300 and 400 pA currents for sham- and CCI-treated mice. Scale bar: 20 mV, 500 ms. There was reduced AP firing in CCI neurons at each current amplitude. (F) Plot of mean firing frequency as a function of current intensity. Note the decreased firing in the CCI-treated neuron relative to the sham-treated neuron (n = 12–13 neurons, n = 7–11 mice per group). (G) I-V curve showed a significant decrease in slope for neurons from CCI-treated animals (**P = 0.001, Mann-Whitney U test; n = 12–13 neurons, n = 7–11 mice per group). (H) CCI neurons showed increased rheobase (*P = 0.04, unpaired t test; n = 12–13 neurons, n = 7–11 mice per group). (I) Schematics show voltage-clamp recordings of incoming excitatory synaptic information that neurons receive across their dendritic arbors. (J) Typical voltage-clamp recordings show spontaneous inward excitatory currents in layer 2/3 pyramidal cells of the sensory cortex of sham- and CCI-treated mice. Scale bar: 200 pA, 10 seconds. (K) Mean IEIs were longer (frequency was decreased) in cells from CCI-treated animals (*P = 0.03, 2-sided Mann-Whitney U test; n = 6–7 neurons, n = 6–7 mice per group). No differences in the AUC of excitatory currents were observed between groups (right plot: P > 0.05, 2-sided Mann-Whitney U test; n = 6–7 neurons, n = 6–7 mice per group).