Alterations in basic membrane properties of Hu97/18

<p>SPNs. (A–C): Membrane capacitance (A), membrane resistance (B), and membrane time constant (C) did not differ between Hu18/18 and Hu97/18 SPNs. Membrane capacitance measurement was pooled from the experiments with potassium-based and caesium-based internal solutions (Hu18/18 n = 46, Hu97/18 n = 44), while membrane resistance and tau were measured with potassium-based internal solution only (Hu18/18 n = 21, Hu97/18 n = 17). (D – J): Cells were patch-clamped with potassium-based solution, and membrane voltage changes in response to the injected current were recorded and analysed. (D) Representative I–V response of a Hu18/18 SPN to current injection (50pA increments from -200pA, 1 s each). (E) I–V curves showed no difference between Hu97/18 and Hu18/18 SPNs. (F) Rheobase and (G) rheobase frequency were not different between the genotypes. (H) Hu97/18 had a lower resting membrane potential than Hu18/18 SPNs (p = 0.03). (I) Action potential (AP) threshold was more depolarized in Hu97/18 SPNs (p = 0.02). (J) The change in membrane voltage from resting potential to AP threshold was not different between Hu18/18 and Hu97/18 SPNs. For the experiments in D–J, Hu18/18 n = 11 and Hu97/18 n = 12. *p<0.05 (unpaired Student’s t-test).