The array of these astrocyte-delimited microdomains along the capillary microvasculature allows the formation of higher-order gliovascular units, which serve to match local neural activity and blood flow while regulating neuronal firing thresholds through coordinative glial signaling.
In other words, at each moment, the neuronal activity could exceed the firing threshold with a certain probability, even if the deterministic activity is below the firing threshold.
BoNT‐A treatment had no effect on the overall neuronal excitability, characterized by the firing threshold in response to current injection, or on the membrane resting potential, as shown in Figure 3. RA and intermediately adapting mechanically activated inward currents were unchanged.
This fundamental reasoning, based on the observation that the depolarization block occurring during evoked seizures represents an upper threshold for neuronal firing, also supports replacing a sigmoidal nonlinearity by a Gaussian-like activation function.
1We assume that all neurons have the same firing threshold.
Importantly, these autoantibodies stained neurons and inhibited neuronal firing in brain slices (Levin et al, 2002).
Pyrethroids affect nervous system function by producing hyperexcitability in neurons and changing neuronal firing rates [ 18- 21].
The mechanism of tDCS involves changing the spontaneous neuronal firing rate and therefore the resting membrane threshold, influencing polarization.
Cav1.3 comprises only ~10% of the LTCCs in the brain (8), but because of its more negative activation voltage range, it can carry inward calcium currents at threshold voltages (9,10), shaping neuronal firing patterns and contributing to pacemaker currents (2,6,7,11).
During evoked seizures in cortical slices prepared from this brain tissue, single neurons show a strong paroxysmal depolarization, indicating an arrest of neuronal firing after high-level synaptic input exceeds an (upper) threshold; see e.g. [7].
