Fig. 4. Aging does not affect membrane properties and excitability of pyramidal neurons.
a Representative currents recorded in cortical pyramidal neurons in response to 5 mV voltage steps in younger (left) and older (right) adults. b Input resistance (Ri) of neurons in two age groups (P = 0.66; younger adults: N = 4 people; older adults: N = 4 people; cell number n = N). c Action potentials (APs) recorded in current-clamp mode in response to current steps 200 pA, 320 pA, and 440 pA in younger (top) and older (bottom) adults. d Maximal frequency of Aps (P = 0.3); e rheobase (P = 0.9); f afterhyperpolarization (AHP, P = 0.99); g AP adaptation (P = 0.5); h AP overshoot (P = 0.9); i AP half-width in younger and older adults (N/n—numbers the same as for (b)). Data are shown as box-and-whisker plots where the box is Q1 and Q3 with median, and whiskers are the ranges within 1.5IQR. Empty boxes/circles—younger adults, filled boxes/circles—older adults. Two-tailed Mann–Whitney test: N.S.P > 0.05. Source data are provided as a Source Data file.