README
¶
knadapt
Package knadapt provides code for sodium (Na) gated potassium (K) currents that drive adaptation (accommodation) in neural firing. As neurons spike, driving an influx of Na, this activates the K channels, which, like leak channels, pull the membrane potential back down toward rest (or even below). Multiple different time constants have been identified and this implementation supports 3: M-type (fast), Slick (medium), and Slack (slow)
Here's a good reference:
Kaczmarek, L. K. (2013). Slack, Slick, and Sodium-Activated Potassium Channels. ISRN Neuroscience, 2013. https://doi.org/10.1155/2013/354262
This package supports both spiking and rate-coded activations.
Spiking
The logic is simplest for the spiking case:
if spike {
gKNa += Rise * (Max - gKNa)
} else {
gKNa -= 1/Tau * gKNa
}
The KNa conductance ($g_{kna}$ in mathematical terminology, gKNa in the program) rises to a Max value with a Rise rate constant, when the neuron spikes, and otherwise it decays back down to zero with another time constant Tau.
Rate code
The equivalent rate-code equation just substitutes the rate-coded activation variable in as a multiplier on the rise term:
gKNa += act * Rise * (Max - gKNa) - (1/Tau * gKNa)
Defaults
The default parameters, which were fit to various empirical firing patterns and also have proven useful in simulations, are:
| Channel Type | Tau (ms) | Rise | Max |
|---|---|---|---|
| Fast (M-type) | 50 | 0.05 | 0.1 |
| Medium (Slick) | 200 | 0.02 | 0.1 |
| Slow (Slack) | 1000 | 0.001 | 1.0 |
Documentation
¶
Overview ¶
Package knadapt provides code for sodium (Na) gated potassium (K) currents that drive adaptation (accommodation) in neural firing. As neurons spike, driving an influx of Na, this activates the K channels, which, like leak channels, pull the membrane potential back down toward rest (or even below). Multiple different time constants have been identified and this implementation supports 3: M-type (fast), Slick (medium), and Slack (slow)
Here's a good reference:
Kaczmarek, L. K. (2013). Slack, Slick, and Sodium-Activated Potassium Channels. ISRN Neuroscience, 2013. https://doi.org/10.1155/2013/354262
This package supports both spiking and rate-coded activations.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Chan ¶
type Chan struct {
// if On, use this component of K-Na adaptation
On bool
// Rise rate of fast time-scale adaptation as function of Na concentration -- directly multiplies -- 1/rise = tau for rise rate
Rise float32
// Maximum potential conductance of fast K channels -- divide nA biological value by 10 for the normalized units here
Max float32
// time constant in cycles for decay of adaptation, which should be milliseconds typically (roughly, how long it takes for value to change significantly -- 1.4x the half-life)
Tau float32
// 1/Tau rate constant
Dt float32 `display:"-"`
}
Chan describes one channel type of sodium-gated adaptation, with a specific set of rate constants.
func (*Chan) GcFromRate ¶
GcFromRate updates the KNa conductance based on rate-coded activation. act should already have the compensatory rate multiplier prior to calling.
func (*Chan) GcFromSpike ¶
GcFromSpike updates the KNa conductance based on spike or not
func (*Chan) ShouldDisplay ¶
type Params ¶
type Params struct {
// if On, apply K-Na adaptation
On bool
// extra multiplier for rate-coded activations on rise factors -- adjust to match discrete spiking
Rate float32 `default:"0.8"`
// fast time-scale adaptation
Fast Chan `display:"inline"`
// medium time-scale adaptation
Med Chan `display:"inline"`
// slow time-scale adaptation
Slow Chan `display:"inline"`
}
Params describes sodium-gated potassium channel adaptation mechanism. Evidence supports at least 3 different time constants: M-type (fast), Slick (medium), and Slack (slow)
func (*Params) GcFromRate ¶
GcFromRate updates all time scales of KNa adaptation from rate code activation
func (*Params) GcFromSpike ¶
GcFromSpike updates all time scales of KNa adaptation from spiking
Source Files