Measurement of action potential parameters and firing patterns. A, B: Measurement of action potential parameters. 1) Resting membrane potential (mV); 2) Action potential threshold (mV); 3) Action potential amplitude (mV); 4) After hyperpolarization (AHP) amplitude (mV); 5) AHP duration (ms); 6,)Spike rise time (ms); 7) Spike decay time (ms); 8) Spike duration; 9), Spike half width (ms). C, D: Measurement of parameters of firing properties of a medial septal and diagonal band complex neuron subjected to a depolarizing current pulse: time interval between: 1, the first two action potentials; 2, the last two action potentials. Reciprocal of time intervals gives maximum firing frequency (FMAX) and steady firing frequency (FSTEADY). Scale bars: 20 mV, 50 ms in A; 20 mV, 0.5 ms in B; 20 mV, 100 ms in C.