brainpy.dyn.channels.ICaT#

class brainpy.dyn.channels.ICaT(size, T=36.0, T_base_p=3.55, T_base_q=3.0, g_max=2.0, V_sh=- 3.0, method='exp_auto', name=None)[source]#

The low-threshold T-type calcium current model.

The dynamics of the low-threshold T-type calcium current model 1 is given by:

\[\begin{split}I_{CaT} &= g_{max} p^2 q(V-E_{Ca}) \\ {dp \over dt} &= {\phi_p \cdot (p_{\infty}-p)\over \tau_p} \\ &p_{\infty} = {1 \over 1+\exp [-(V+59-V_{sh}) / 6.2]} \\ &\tau_{p} = 0.612 + {1 \over \exp [-(V+132.-V_{sh}) / 16.7]+\exp [(V+16.8-V_{sh}) / 18.2]} \\ {dq \over dt} &= {\phi_q \cdot (q_{\infty}-q) \over \tau_q} \\ &q_{\infty} = {1 \over 1+\exp [(V+83-V_{sh}) / 4]} \\ & \begin{array}{l} \tau_{q} = \exp \left(\frac{V+467-V_{sh}}{66.6}\right) \quad V< (-80 +V_{sh})\, mV \\ \tau_{q} = \exp \left(\frac{V+22-V_{sh}}{-10.5}\right)+28 \quad V \geq (-80 + V_{sh})\, mV \end{array}\end{split}\]

where \(phi_p = 3.55^{\frac{T-24}{10}}\) and \(phi_q = 3^{\frac{T-24}{10}}\) are temperature-dependent factors (\(T\) is the temperature in Celsius), \(E_{Ca}\) is the reversal potential of Calcium channel.

Parameters
  • T (float) – The temperature.

  • T_base_p (float) – The base temperature factor of \(p\) channel.

  • T_base_q (float) – The base temperature factor of \(q\) channel.

  • g_max (float) – The maximum conductance.

  • V_sh (float) – The membrane potential shift.

References

1

Huguenard JR, McCormick DA (1992) Simulation of the currents involved in rhythmic oscillations in thalamic relay neurons. J Neurophysiol 68:1373–1383.

__init__(size, T=36.0, T_base_p=3.55, T_base_q=3.0, g_max=2.0, V_sh=- 3.0, method='exp_auto', name=None)[source]#

Methods

__init__(size[, T, T_base_p, T_base_q, ...])

current(V, C_Ca, E_Ca)

dp(p, t, V)

dq(q, t, V)

get_delay_data(name, delay_step, *indices)

Get delay data according to the provided delay steps.

ints([method])

Collect all integrators in this node and the children nodes.

load_states(filename[, verbose])

Load the model states.

nodes([method, level, include_self])

Collect all children nodes.

register_delay(name, delay_step, delay_target)

Register delay variable.

register_implicit_nodes(nodes)

register_implicit_vars(variables)

reset(V, C_Ca, E_Ca)

Reset function which reset the whole variables in the model.

save_states(filename[, variables])

Save the model states.

train_vars([method, level, include_self])

The shortcut for retrieving all trainable variables.

unique_name([name, type_])

Get the unique name for this object.

update(t, dt, V, C_Ca, E_Ca)

The function to specify the updating rule.

vars([method, level, include_self])

Collect all variables in this node and the children nodes.

Attributes

global_delay_targets

global_delay_vars

name

steps