Figure 19

Reset of slow state variables of IB cell at bursting. (a) Apical dendrite h-current gating variable. Each trace corresponds to a burst and is centered so that 0 on the time axis corresponds to the initiation of the burst. The h-current gating variable (vertical axis) drops to approximately 0 at the initiation of each burst (0 on the horizontal axis). (b) Same as (a), for basal dendrite. This variable also resets to approximately 0 at each burst. (c), (d) Same as (a), (b), but for the M-current gating variables. These variable also reset to approximately fixed numbers when the cell begins to burst, around 0.045 in both cases. (e) Same as (c), (d), but for the axon compartment. The traces are color-coded according to the number of spikes in the burst (blue: 2 spikes, red: 3 spikes, black: 4 spikes). The M-current gating variable resets to one of three values (approximately 0.05, 0.07, or 0.09) after a burst, depending on the number of spikes in the burst. (f) Same as (e), but for the state variable of the IB \(a\to d_{b}\) (axon to basal dendrite) synapse. This variable resets to approximately 1 after each burst, but the time it retains this value is variable, depending on the number of spikes in the burst. The resulting differences in the value at a given time after the burst are small. (g) Same as (a)–(e), but for the SI→IB synaptic state variable. This variable does not reset when the IB cell bursts, but its value is always between 0.1 and 0.2 at the beginning of a burst. Simulation parameters are as in Fig. 16(c)