Table 1.

Basic neuronal parameters in young-adult and aged CA1 neurons

Young-adult (n = 15)Aged (n = 16)
Input resistance (MΩ)58.9  ± 3.761.9  ± 3.3
Resting membrane potential (mV)−58.7  ± 1.1−58.8  ± 1.3
Action potential threshold (μA)151  ± 15181  ± 15
Action potential amplitude (mV)83.8  ± 1.381.9  ± 2.3
Action potential width at base (msec)2.3  ± 0.22.4  ± 0.1
Action potentials during 20 sec train (n)134.6  ± 8.4126.9  ± 8.1
Action potentials during FFearly (n)14  ± 014  ± 0
Action potentials during FFlate(n)11.2  ± 1.310.2  ± 1.3
Interval, slicing to imaging (hr)3.85  ± 0.44.3  ± 0.3
  • All values are mean ± SEM. No significant age-dependent differences were detected. Threshold was the synaptic stimulation electrode current necessary to trigger a Na+ action potential. Action potential amplitude was measured from the peak of the EPSP. Action potential number values (n) were obtained during the 7 Hz suprathreshold train of synaptic activation.