sorted

Glossary

Common abbreviations in NEST

iaf

Integrate and fire.

gif

Generalized integrate and fire.

cond

Conductance-based.

psc

Post-synaptic current (current-based).

hh

Hodgkin huxley.

rng

Random number generator.

wfr

Waveform relaxation method.

aeif

Adaptive exponential integrate and fire.

ht

Hill and tononi.

pp

Point process.

in

Inhibitory.

ex

Excitatory.

MAM

Multi-area model.

mpi

Message passing interface.

stdp

Spike-timing dependent plasticity synapse.

st

Short term plasticity.

vp

Virtual process.

time

Milliseconds (ms).

tau_m

Membrane time constant in milliseconds (ms).

t_ref

Duration of refractory period in milliseconds (ms).

t_spike

Point in time of last spike in milliseconds (ms).

capacitance

Picofarads (pF).

C_m

Capacitance of the membrane in picofarads (pF).

current

Picoamperes (pA).

I_e

Constant input current in picoamperes (pA).

conductance

Nanosiemens (nS).

g_L

Leak conductance in Nanosiemens (nS).

g_K

Potassium peak conductance in Nanosiemens (nS).

g_Na

Sodium peak conductance in Nanosiemens (nS).

spike rates

Spikes/second.

modulation frequencies

Herz (Hz).

frequency

Frequncy in Hertz (Hz).

voltage

Millivolts (mV).

V_m

Membrane potential in Millivolts (mV).

E_L

Resting membrane potential in Millivolts (mV).

V_th

Spike threshold in Millivolts (mV).

V_reset double

Reset potential of the membrane in Millivolts (mV).

V_min

Absolute lower value for the membrane potential in Millivolts (mV).

E_ex

Excitatory reversal potential in Millivolts (mV).

E_in

Inhibitory reversal potential in Millivolts (mV).

E_Na

Sodium reversal potential in Millivolts (mV).

E_K

Potassium reversal potential in Millivolts (mV).

subthreshold dynamics

Non-spiking backgound activity of the synapses.

refractory period

A time period in which neurons cannot fire. This is due to depolarization.

shotnoise

Fluctuations in ion channels as a result of ionic migration through an open channel.

autapse

A neuron connected to itself.

multapse

A neuron that has (multiple) synapses with another neuron.

spike-timing dependent plasticity

STDP, a form of plasticity which adjusts the connection strength between neurons based on the relative timing of a neurons output and input spikes.

spike train

A sequence of actions potentials. Usually seen as events in integrate-and-fire models.

depressing window

A function that determines how synaptic modification depends on spike-timing (STDP).

dendritic arbor

Dendritic trees formed to create new synapses.

axon

The output structure of a neuron.

Clopath

Refering to the Clopath plasticity rule.

plasticity

The ability of a network to grow or reorganize.

Hodgkin-Huxley

A mathematical model that describes how action potentials in neurons can be generated and how they propagate.

refractory time

A time period in which neurons cannot fire due to depolarization.

Point process

A temporal point process is a mathematical model for a time series of discrete events.

non-renewal process

Point process with adapting threshold eta(t).

rheobase

The minimal current that is required to generate a spike.

reversal potential

The membrane potential at which a neuron causes no net current flow.

time constant

The time it takes for a signal to rise or decay in milliseconds (ms).

See membrane time constant (tau_m) and synaptic time constant (tau_syn) in the model documentation.

Gaussian white noise

A random process with a mean of zero.

sfa

Spike-frequency adaptation.

point neuron

A simple neuron model where its soma along with the membrane potential dynamics are modeled as a resistance–capacitance circuit.

propagator

Matrix used in a numerically integrated dynamical system.

See exact integration page for further information.

synaptic response kernel

Shape of post-synaptic response, commonly an alpha, delta-pulse, or exponential function.

eligibility trace

A property of a synapse, which allows it to be modified for a period of time when some constraints are satisfied.

reversal potential

The membrane potential in which a neuron causes no net current flow.

alpha function

Instance of a synaptic response.

facilitation

Mechanism of making a synapse stronger by increasing the weight.

Opposite to depression.

depression

Mechanism of making a synapse weaker by decreasing the weight.

Opposite to facilitation.

stdp_synapse

Synapse with spike-timing dependent plasticity.

static_synapse

Synapse with a fixed weight.

refractoriness

The time before a new action potential can take place.

renewal process

Spike-time statistical analysis.

spike train

A sequence of action potentials.

spike-frequency adaptation

After stimulation, neurons show a reduction in the firing frequency of their spike response following an initial increase.

GIF

Generalized integrate-and-fire model.

coefficient of variation

Standard deviation divided by the mean.

distal dendrite

The part of the dentrite that is furthest away from the soma.

proximal dendrite

The part of the dentrite which is closest to the soma.

soma

Cell body of the neuron.

psp

Post-synaptic potential.

PSC

Post-synatpic current.

absolute refractory

An interval after a neuron fires a spike to prevent it from firing a spike again.

indegree

Amount of connections to post-synaptic cells.

outdegree

Amount of connections from pre-synaptic cells.

synaptic efficacy

The extent to which a pre-synaptic neuron affects a post-synaptic neuron.

multimeter

A device to record analog quantities (e.g., membrane voltage) of a neuron over time.

events

Spikes are encoded as events in NEST.