:orphan: .. _glossary: Glossary ======== .. _units_measure: Units of measure --------------- .. glossary:: :sorted: time Time in 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 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). .. _model_terms: Terms for models in NEST ------------------------ .. glossary:: :sorted: iaf Integrate-and-fire. Also known in other sources as `IF`. gif Generalized integrate-and-fire. From the Gerstner lab. glif Generalized leaky integrate-and-fire. From the Allen institute. cond Conductance-based. Also known in other sources as `COBA`. psc Post-synaptic current (current-based). Also known in other sources as `CUBA`. hh Hodgkin Huxley. aeif Adaptive exponential integrate-and-fire. Also known in other sources as `AdEx`. ht Hill and Tononi. pp Point process. in Inhibitory. ex Excitatory. stdp Spike-timing dependent plasticity. st Short-term plasticity. psp Post-synaptic potential. sfa Spike-frequency adaptation. cm Compartmental model. Other abbreviations ------------------- .. glossary:: :sorted: rng Random number generator. wfr Waveform relaxation method. MAM Multi-area model. mpi Message passing interface. vp Virtual process. Commonly used terms in NEST ---------------------------- .. glossary:: :sorted: 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. 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 :ref:`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. 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-frequency adaptation After stimulation, neurons show a reduction in the firing frequency of their spike response following an initial increase. 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. absolute refractory period Interval directly following a spike emission in which the sender neuron cannot fire 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.