Table 1 Default parameters of the LIF network model

From: A Python toolbox for neural circuit parameter inference

Symbol

Value/definition

Description

X

{E, I}

Population names

NX {NE, NI}

{8192, 1024}

Population sizes

CYX

0.2 for all X, Y

Connection probability (pairwise Bernoulli, no autapses)

CmX

{289.1, 110.7} pF

Membrane capacitance

τm

10 ms for all X

Membrane time constant

RmX

τm/CmX

Membrane resistance

EL

-65 mV for all X

Leak reversal potential

Vθ

-55 mV for all X

Spike threshold

Vr

EL for all X

Spike reset potential

τr

2 ms for all X

Refractory period

\({{\rm{t}}}_{{\rm{k}}}^{\left\langle {\rm{u}}\right\rangle }\)

\({\rm{if}}{{\rm{V}}}_{{\rm{m}}}^{\left\langle {\rm{u}}\right\rangle }\left({{\rm{t}}}_{{\rm{k}}}^{\left\langle {\rm{u}}\right\rangle }\right)\ge {{\rm{V}}}_{{\rm{\theta }}}\)

Spike emission times; 〈u〉 is the neuron index

\({{\rm{\tau }}}_{{\rm{m}}}\frac{{\rm{d}}{{\rm{V}}}_{{\rm{m}}}^{\left\langle {\rm{u}}\right\rangle }}{{\rm{dt}}}\)

\({-{\rm{V}}}_{{\rm{m}}}^{\left\langle {\rm{u}}\right\rangle }+{{\rm{R}}}_{{\rm{mX}}}{{\rm{I}}}_{{\rm{u}}}\left({\rm{t}}\right)\,{\rm{if}}\,\forall {\rm{k}},{\rm{t}}\,\notin \left({{\rm{t}}}_{{\rm{k}}}^{\left\langle {\rm{u}}\right\rangle },{{\rm{t}}}_{{\rm{k}}}^{\left\langle {\rm{u}}\right\rangle }+\left.{{\rm{\tau }}}_{{\rm{r}}}\right]\right.\)

Sub-threshold dynamics; Iu(t) is the synaptic activation current

\({{\rm{V}}}_{{\rm{m}}}^{\left\langle {\rm{u}}\right\rangle }({\rm{t}})\)

\({{\rm{V}}}_{{\rm{r}}}{\rm{if}}\,{\rm{t}}\in \left({{\rm{t}}}_{{\rm{k}}}^{\left\langle {\rm{u}}\right\rangle },{{\rm{t}}}_{{\rm{k}}}^{\left\langle {\rm{u}}\right\rangle }+\left.{{\rm{\tau }}}_{{\rm{r}}}\right]\right.\)

Reset and refractoriness

\({\bar{{\rm{J}}}}_{{\rm{synYX}}}\)

\(\left\{\begin{array}{c}1.589{\rm{nA\; for}}{\rm{X}}={\rm{E}},{\rm{Y}}={\rm{E}}\\ 2.020{\rm{nA\; for}}{\rm{X}}={\rm{E}},{\rm{Y}}={\rm{I}}\\ -23.84{\rm{nA\; for}}{\rm{X}}={\rm{I}},{\rm{Y}}={\rm{E}}\\ -8.441{\rm{nA\; for}}{\rm{X}}={\rm{I}},{\rm{Y}}={\rm{I}}\end{array}\right.\)

Mean of the normal distribution that defines the maximum synaptic current of recurrent connections

σ(JsynYX)

\(0.1\left|{\bar{{\rm{J}}}}_{{\rm{synYX}}}\right|\)

Standard deviation of the maximum synaptic current

\({{\rm{\tau }}}_{{\rm{syn}}}^{{\rm{exc}}}\), \({{\rm{\tau }}}_{{\rm{syn}}}^{{\rm{inh}}}\)

0.5 ms

Exp. syn. decay time constant

\({\bar{\Delta }}_{{\rm{YX}}}\)

\(\left\{\begin{array}{c}2.520{\rm{ms\; for}}{\rm{X}}={\rm{E}},{\rm{Y}}={\rm{E}}\\ 1.714{\rm{ms\; for}}{\rm{X}}={\rm{E}},{\rm{Y}}={\rm{I}}\\ 1.585{\rm{ms\; for}}{\rm{X}}={\rm{I}},{\rm{Y}}={\rm{E}}\\ 1.149{\rm{ms\; for}}{\rm{X}}={\rm{I}},{\rm{Y}}={\rm{I}}\end{array}\right.\)

Mean of the normal distribution that defines conduction delays of recurrent connections

σ(ΔYX)

\(0.5{\bar{\Delta }}_{{\rm{YX}}}\)

Standard deviation of conduction delays

\({{\rm{J}}}_{{\rm{syn}}}^{{\rm{ext}}}\)

29.89 nA

Max. synaptic current of ext. input

\({{\rm{k}}}_{{\rm{Y}}}^{{\rm{ext}}}\)

{465, 160}

Ext. synapses per neuron

\(\left\langle {{\rm{\upsilon }}}_{{\rm{ext}}}\right\rangle\)

40 s-1 (Poisson statistics)

Ext. syn. activation rate