CaHT_Re1993

class braincell.channel.CaHT_Re1993(size, g_max=Quantity(1., 'mS / cm^2'), temp=Quantity(309.15, 'K'), q10_p=2.3, temp_ref_p=Quantity(296.15, 'K'), q10_q=2.3, temp_ref_q=Quantity(296.15, 'K'), V_sh=Quantity(0., 'mV'), name=None)

Reuveni 1993 high-threshold calcium current.

The high-voltage-activated (HVA) calcium current underlying the calcium plateau spike in neocortical pyramidal cells, from (Reuveni et al., 1993) [1], with \(p^2 q\) HH gating (an \(m^2 h\) scheme in the source mod file’s naming) and an ohmic driving force:

\[\begin{split}\begin{aligned} \alpha_p &= \frac{0.055 (V'' - 27)}{\exp((V'' - 27) / 3.8) - 1} \\ \beta_p &= 0.94 \exp((V'' - 75) / 17) \\ \alpha_q &= 0.000457 \exp((V'' - 13) / 50) \\ \beta_q &= \frac{0.0065}{\exp((V'' - 15) / 28) + 1} \end{aligned}\end{split}\]

where \(V'' = (V_{sh} - V) / \mathrm{mV}\) is the negated- voltage form the source mod file uses inline, so with the default V_sh = 0.0 mV this reduces to \(V'' = -V / \mathrm{mV}\).

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 1.0 mS/cm2.

• temp (Array | ndarray | bool | number | bool | int | float | complex | Quantity) – Absolute temperature driving the Q10 factors, default 36 degrees Celsius.

• q10_p (Array | ndarray | bool | number | bool | int | float | complex | Quantity | Callable) – Q10 scaling factor for the activation gate, default 2.3.

• temp_ref_p (Array | ndarray | bool | number | bool | int | float | complex | Quantity) – Reference temperature for q10_p, default 23 degrees Celsius.

• q10_q (Array | ndarray | bool | number | bool | int | float | complex | Quantity | Callable) – Q10 scaling factor for the inactivation gate, default 2.3.

• temp_ref_q (Array | ndarray | bool | number | bool | int | float | complex | Quantity) – Reference temperature for q10_q, default 23 degrees Celsius.

• V_sh (Array | ndarray | bool | number | bool | int | float | complex | Quantity | Callable) – Threshold shift entering the negated-voltage form above, default 0.0 mV.

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

See also

CaHT_HM1992

Nominally also a high-threshold current, but actually a relabelled low-threshold T current with no genuine high-threshold attribution (see its Notes).

Notes

Compared against ca.mod (ModelDB accession 2488), headed “HVA Ca current / Based on Reuveni, Friedman, Amitai and Gutnick (1993) / J. Neurosci. 13:4609-4621” (implementation by Zach Mainen, Salk Institute, 1994). Every rate constant above matches the mod file’s alpha_m/beta_m/alpha_h/beta_h term for term, and the temperature parameters match exactly: ca.mod uses temp = 23 degC, q10 = 2.3; this class defaults to q10_p = q10_q = 2.3 at temp_ref = 23 degC. Gating is \(m^2 h\) in both.

References

[1]

Reuveni, I., Friedman, A., Amitai, Y., & Gutnick, M. J. (1993). Stepwise repolarization from Ca2+ plateaus in neocortical pyramidal cells: evidence for nonhomogeneous distribution of HVA Ca2+ channels in dendrites. The Journal of Neuroscience, 13(11), 4609-4621. doi:10.1523/JNEUROSCI.13-11-04609.1993

root_type

alias of Calcium