Table 2.

Properties of CA1 neurons from young and aged rabbits that do not change after acquisition of trace eyeblink conditioning

Group (number of rabbits)Resting potential (n)Time constant (n)Input resistance (n)Action potential characteristics (n) 2-a
Mean, mVMean, msecMean, MΩAmplitude, mVWidth, msec
Naive, young (4)−67.9  ± 0.9  (15)17.3  ± 1.7  (15)32.1  ± 1.8  (15)100.8  ± 1.5  (11)1.3  ± .06  (11)
Naive, aged (6)−67.3  ± 0.4  (13)17.8  ± 2.3  (13)34.8  ± 2.4  (13)97.6  ± 1.5  (13)1.3  ± .03  (13)
Slow learners, young (4)−66.5  ± 0.5  (11)15.7  ± 1.4  (11)34.0  ± 3.4  (11)98.9  ± 1.5  (10)1.3  ± .04  (10)
Slow learners, aged (5)−67.8  ± 0.6  (11)19.0  ± 2.0  (10)30.9  ± 2.1  (11)99.7  ± 2.0  (7)1.4  ± .04  (7)
Trace 60%, young (6)−68.7  ± 0.8  (15)14.9  ± 1.0  (15)30.9  ± 1.6  (15)102.3  ± 1.9  (11)1.4  ± .19  (11)
Trace 60%, aged (7)−68.9  ± 0.6  (19)16.1  ± 1.1  (17)32.1  ± 1.4  (18)102.8  ± 3.1  (16)1.4  ± .06  (16)
Trace 80%, young (3)−67.1  ± 0.6  (9)15.2  ± 3.5  (7)37.5  ± 3.2  (7)97.6  ± 1.4  (6)1.3  ± .07  (6)
Trace 80%, aged (1)−68.3  ± 0.5  (4)17.1  ± 1.2  (4)32.7  ± 1.2  (4)103.3  ± 6.7  (3)1.6  ± .05  (3)
  • F2-a Antidromic action potentials were used to allow for accurate width measurements without interference from the underlying depolarizing potential that occurs using current injection-evoked or orthodromically driven action potentials.