sKdr_SU2015_DCN

sKdr_SU2015_DCN#

class braincell.channel.sKdr_SU2015_DCN(size, g_max=Quantity(0.01, 'mS / cm^2'), name=None)#

Slow delayed rectifier of the DCN model (Sudhakar 2015).

The slow delayed-rectifier potassium current of the deep cerebellar nucleus (DCN) neuron model used by (Sudhakar et al., 2015) [2], with \(m^4\) HH gating and an ohmic driving force:

\[\begin{split}\begin{aligned} m_\infty &= \frac{1}{1 + \exp((V + 50) / -9.1)} \\ \tau_m &= \left(\frac{14.95} {\exp((V + 50) / 21.74) + \exp((V + 50) / -13.91)} + 0.05\right) \Big/ q_{\Delta t} \end{aligned}\end{split}\]

where \(V\) is in millivolts – this class applies no voltage shift – and \(\tau_m\) is in milliseconds. The reversal potential comes from the potassium ion object, not from the class. Compared with fKdr_SU2015_DCN, activation is 10 mV more hyperpolarized and shallower.

Parameters:

  • size (int | Sequence[int] | integer | Sequence[integer]) – Channel state shape.

  • g_max (Array | ndarray | bool | number | bool | int | float | complex | Quantity | Callable) – Maximal conductance density. Defaults to 0.01 mS/cm2, which is exactly the source mechanism’s gbar = 1e-5 siemens/cm2.

  • name (str | None) – Optional channel name.

See also

fKdr_SU2015_DCN

Fast delayed rectifier of the same DCN model, with the same gating shape.

braincell.channel.NaF_SU2015_DCN

Fast sodium current of the same model.

Notes

Ported from DCN/channel/sKdr_SU15_DCN.mod, whose COMMENT reads “Translated from GENESIS by Johannes Luthman and Volker Steuber.” Accordingly, the kinetics originate in the GENESIS deep cerebellar nucleus model of Steuber, Schultheiss, Silver, De Schutter & Jaeger (2011) [1], were translated from GENESIS to NEURON by Luthman, Hoebeek, Maex, Davey, Adams, De Zeeuw & Steuber (2011), and were used in that translated form by Sudhakar et al. (2015) [2]. The 2011 translation paper is named in this prose only, per house style, and not as a numbered reference.

What this docstring does not claim. No paper in that chain was shown to print the Boltzmann and time-constant constants above; the code-side check ran from the .mod file to this class only. The string “sKdr” does not occur anywhere in the Sudhakar et al. (2015) text, so this records that the mechanism is part of the model published as [2], not that the paper names or describes it.

qdeltat is set to 1.0 in __init__() as a fixed attribute rather than exposed as a constructor parameter; it mirrors the mod file’s GLOBAL qdeltat and divides \(\tau_m\) as shown.

Import deviation. The original mechanism’s NMODL TABLE over [-150, 100] mV, covering minf and taum, is not reproduced: both expressions are evaluated per call. NEURON clamped tabulated values to the boundary outside that window, so any BrainCell-versus-NEURON divergence below -150 mV or above 100 mV is expected rather than a port error.

References

root_type#

alias of Potassium