tsodyks2_synapse – Synapse type with short term plasticity

Description

This synapse model implements synaptic short-term depression and short-term facilitation according to [1] and [2]. It solves Eq (2) from [1] and modulates U according to eq. (2) of [2].

This connection merely scales the synaptic weight, based on the spike history and the parameters of the kinetic model. Thus, it is suitable for all types of synaptic dynamics, that is current or conductance based.

The parameter A_se from the publications is represented by the synaptic weight. The variable x in the synapse properties is the factor that scales the synaptic weight.

Warning

This synaptic plasticity rule does not take precise spike timing into account. When calculating the weight update, the precise spike time part of the timestamp is ignored.

See also [3].

Under identical conditions, the tsodyks2_synapse produces slightly lower peak amplitudes than the tsodyks_synapse. However, the qualitative behavior is identical. The script Example of the tsodyks2_synapse in NEST compares the two synapse models.

Parameters

The following parameters can be set in the status dictionary:

U	real	Parameter determining the increase in u with each spike (U1) [0,1], default = 0.5
u	real	The probability of release (U_se) [0,1], default = U
x	real	Current scaling factor of the weight, default = 1.0
tau_fac	ms	Time constant for facilitation, default = 0 (off)
tau_rec	ms	Time constant for depression, default = 800

References

[1] (1,2)

Tsodyks MV, Markram H (1997). The neural code between neocortical pyramidal neurons depends on neurotransmitter release probability. PNAS, 94(2):719-23. DOI: https://doi.org/10.1073/pnas.94.2.719

[2] (1,2)

Fuhrman, G, Segev I, Markram H, Tsodyks MV (2002). Coding of temporal information by activity-dependent synapses. Journal of Neurophysiology, 87(1):140-8. DOI: https://doi.org/10.1152/jn.00258.2001

[3]

Maass W, Markram H (2002). Synapses as dynamic memory buffers. Neural Networks, 15(2):155-61. DOI: https://doi.org/10.1016/S0893-6080(01)00144-7

Transmits

SpikeEvent

See also

tsodyks_synapse, stdp_synapse, static_synapse

Examples using this model

• Example for the quantal_stp_synapse

• Example of the tsodyks2_synapse in NEST