Statistical tests are performed with Matlab using, if not otherwise indicated, a Student's t-test in comparison of two datasets, a statistical test comparing the slope of a least-squares linear best fit line to 0, or a least-squares regression to an exponential function when such a trend is expected (subthreshold and action potential attenuation).

1E bottom left, slope = 0.0015 um'l, p = 0.02), and the ratio of voltage threshold for triggering somatic action potentials between dendritic and somatic step current injection (slope = 0.0040 um'l, p = 3.8e-4).

Since the critical frequency experiment depends on action potential generation perisomatically, active backpropagation of action potentials along the apical axis, calcium-dependent nonlinearities in the apical tuft, and the transfer of nonlinear electrogenesis from the tufts back to the somatic electrode, the model fits both somatic and dendritic properties of L5 pyramidal neurons in mouse V1 well.

This line of research has shown that pyramidal neurons in different cortical regions contain voltage-gated Na+ channels along the dendritic trunk which support the backpropagation of action potentials (APs) from the soma into dendrites [6] , as well as voltage-gated Ca2+ channels that support spiking in the apical dendrite [3,7].

We find that mouse L5 pyramidal neurons in V1 support backpropagating action potentials (bAPs), and dendritic Ca2+ spiking.

We show how concurrent input into the perisomatic and electrically remote apical tuft regions switches somatic action potential output from low to high frequency.

We use the multi-compartmental pyramidal cell model [17] to further explore the relationship between the different nonlinearities found in our experiments and their role in the transformation between synaptic input and action potential output.

In the simulations we ask how much input is needed into the dendritic tuft in order to elicit a burst of somatic action potentials given a certain amount of basal input.

Neuronal excitability relies on inward sodium and outward potassium fluxes during action potentials .

Astrocytes from stratum radiatum were recognized by their small soma size (5—10 pm), very low membrane resistance and hyperpolarized resting membrane potentials (w- 80 mV), passive properties of their membrane (linear IV), absence of action potentials , and large coupling through gap junctions.

41), action potential amplitude and firing rate then progressively decreased due to neuronal depolarization (from-33 mV to-19 mV after 14 and 30 seconds of stimulation, respectively), suppressing neuronal firing after 14 seconds of stimulation (Fig.

As performed in several studies [13,16,24] , the neuron is approximated by a single compartment conductance-based neuron containing Na+ and KL voltage gated channels, enabling action potential discharge.

Contrary to action potentials , characterized by a very fast dynamics in the order of a few milliseconds, astroglial K+ buffering lasts tens of seconds.

These models accurately capture two different aspects of postsynaptic spiking: the spike history term captures the fact that immediately after an action potential , the probability of spike generation decreases, while the coupling terms capture the variable (excitatory, in these experiments) effect of the presyn-aptic input (Fig.

For instance, in vivo results show that, although absolute refractoriness lasts only few milliseconds, generation of an action potential can influence the spike threshold for up to 1s [35,36].

This term describes the strong influence that generation of an action potential has on the probability of future spikes.