Glossary

m-type morphological type
e-type electrical type
me-type morpho-electrical type
s-type synapse type
Intrinsic efferent fibres arising from within the neocortical microcircuit
Extrinsic efferent fibres arising from outside the neocortical microcircuit
Synaptic contact  a direct apposition between the axon and dendrites or soma
Synaptic connection the set of all synaptic contacts between the presynaptic axon and the postsynaptic dendrites or soma
Synaptic connection-type (pathway) the set of all connections between pairs of neurons of pre and postsynaptic m-types
Branch order

the number of bifurcations between an axonal or dendritic section and the soma. Branch order is denoted by °. For e.g., 1° refers to the first dendritic branch originating from the soma or the main apical dendrite

Path distance the distance between a given section and the soma measured along the axon or dendrites
Innervation pattern  a histogram of the locations of synapses measured by branch order or path distance
Neuronal convergence the total number of neurons of one m-type targeting a single neuron of another m-type
Neuronal divergence the total number of neurons of one m-type targeted by a single neuron of another m-type
Resting membrane potential (Vm) the membrane potential (in mV) of a single neuron when potential (Vm) electrically inert or in resting state
Membrane time constant (τm) the time taken (in ms) for the neuronal membrane to charge or discharge
Input resistance (Rin) is given by Ohm's law from the difference in membrane potential of a single neuron at the point of a current injection to after it has reached a steady state (Rin=∆V/∆I MΩ)
gsyn the peak conductance (in nS) for a single synaptic contact
Use utilization of synaptic efficacy - analogous to the transmitter release probability at a single synaptic contact
Dep time constant  (in ms) for recovery from depression
Fac time constant  (in ms) for recovery from facilitation
PSP the postsynaptic membrane potential change (in mV) evoked by a presynaptic stimulus; typically an injection of a brief pulse or a train of pulses to the presynaptic soma
Latency the onset time (in ms) measured as the difference between the time to peak of the presynaptic AP and time taken to reach 5% of peak PSP amplitude
Amplitude the difference in the membrane potential (in mV) measured between the peak and baseline 
Rise time the mean time (in ms) to rise from 20% to 80% of peak PSP amplitude
Decay time constant the mean time (in ms) to decay from peak PSP amplitude to baseline constant
Transmission failure an event where the presynaptic stimulus fails to evoke a postsynaptic response
c.v. of PSP the coefficient of variation of the PSP amplitude measured as the ratio of SD and mean

List of single cell stimulus protocols

IDRest Step current injection in soma. Current amplitude is a percentage of the rheobase.
APThreshold Ramp current inject in soma. Current amplitude is a percentage of the rheobase.
APWaveform High resolution (higher sampling frequency) short step current injection in soma. Typically elicits 1 or 2 action potentials.

List of m-types

DAC Descending Axon Cell
NGC-DA Neurogliaform Cell with dense axonal arborization
NGC-SA Neurogliaform Cell with slender axonal arborization
HAC Horizontal Axon Cell
LAC Large Axon Cell
SAC Small Axon Cell
MC Martinotti Cell
BTC Bitufted Cell
DBC Double Bouquet Cell
BP Bipolar Cell
NGC Neurogliaform Cell
LBC Large Basket Cell
NBC Nest Basket Cell
SBC Small Basket Cell 
ChC Chandelier Cell
PC Pyramidal Cell
SP Star Pyramidal Cell
SS Spiny Stellate Cell
TTPC1 Thick-tufted Pyramidal Cell with a late bifurcating apical tuft
TTPC2 Thick-tufted Pyramidal Cell with an early bifurcating apical tuft
UTPC Untufted Pyramidal Cell
STPC Slender-tufted Pyramidal Cell
TPC_L4 Tufted Pyramidal Cell with apical dendrites terminating in layer 4
TPC_L1 Tufted Pyramidal Cell with apical dendrites terminating in layer 1
IPC Pyramidal Cell with inverted apical-like dendrites
BPC Pyramidal Cell with bipolar apical-like dendrites

 

List of s-types

I1 Inhibitory, facilitating
I2 Inhibitory, depressing
I3 Inhibitory, pseudo-linear
E1 Excitatory, facilitating
E2 Excitatory, depressing
E3 Excitatory, pseudo-linear

 

List of e-types

cADpyr continuous Accommodating (Adapting) for pyramidal cells
cAC continuous Accommodating
bAC burst Accommodating
cNAC continuous Non-accommodating
bNAC burst Non-accommodating
dNAC delayed Non-accommodating
cSTUT continuous Stuttering
bSTUT burst Stuttering
dSTUT delayed Stuttering
cIR continuous Irregular
bIR burst Irregular

 

Spike Characteristics

spike characteristics

 

Firing Behavior

firing glossary