On the one hand, indole inhibited voltage-gated K+ channels, increased the temporal width of action potentials fired by L cells, and led to enhanced Ca2+ entry, thereby acutely stimulating GLP-1 secretion.
In the presence of 1 mM indole, we observed that the temporal width of the action potential was increased almost 2-fold.
The width of action potentials, in contrast, was lower at the higher temperature.
Importantly, blockade of A1 receptors in axon shafts increases the width of action potentials, an effect that facilitates synaptic transmission to distant postsynaptic neurons (Sasaki et al., 2011).
They report that this effect on the spiking threshold occurs without changes in amplitude and width of action potentials, as in the present study.
MiniAnalysis 6.0.1 was also used for the measurement of amplitude of action potentials (from threshold defined as the membrane potential at which the rate-of-rise of voltage crossed 50 V/s; Kole and Stuart 2008) and half width of action potentials.
Notably, local activation of axonal AMPA/kainate receptors by glutamate released from periaxonal astrocytes may increase the width of action potentials while they travel down axons (Sasaki et al., 2011).
"The spatial and temporal patterns of action potential initiations were studied in a behaving leech preparation to determine the basis of increased firing that accompanies sensitization, a form of non-associative learning requiring the S-interneurons.
Moreover, the temporal control of action potential propagation could encode a vast amount of information.
Statistical analyses revealed no significant difference in amplitude, frequency or half-width of action potentials between preconditioned and non-preconditioned cells.
Each code is rendered biologically by spatial and temporal arrangement of action potentials.
