### How to implement short-term depression in cortical area?

Posted:

**Mon Jun 22, 2020 2:22 pm**Hi all

I am constructing thalamo-cortical network for slow oscillations. The AMPA and GABAa currents are given by

Isyn = gsyn[O](V-Esyn) in TC cells to PY cells and PY to TC and RE cells. But I need to add synaptic depression by term D in intra cortical network modifying synaptic current by

Isyn = Dgsyn[O](V-Esyn) where D represents the amount of available “synaptic resource” and D is calculated by

Dn+1 = 1-(1-Dn(1-U))exp(-Δt/τ) (Ref: Tsodyks and Markram 1997)

Where Δt is time interval between nth and (n+1)th spike and τ is the time constant of recovery of the synaptic resource and U is the fraction of resources used per action potential.

1. Now I made two files for APMA with different names one for intra-cortical region (which need synaptic depression addition) and other for thalamocortical (normal) connections. Is it right way or single AMPA file can calculate both currents (simple synaptic current and current with synaptic depression).

2. How can I add synaptic depression D in equation? I am not expert in NEURON. Is it possible to multiply D in BREAKPOINT block like mgblock in NMDA receptor or there is some other method? How can we calculate time between two spikes(nth and (n+1)th spike)?Would you suggest some project or code, which help me.

I will wait for your kind reply.

I am constructing thalamo-cortical network for slow oscillations. The AMPA and GABAa currents are given by

Isyn = gsyn[O](V-Esyn) in TC cells to PY cells and PY to TC and RE cells. But I need to add synaptic depression by term D in intra cortical network modifying synaptic current by

Isyn = Dgsyn[O](V-Esyn) where D represents the amount of available “synaptic resource” and D is calculated by

Dn+1 = 1-(1-Dn(1-U))exp(-Δt/τ) (Ref: Tsodyks and Markram 1997)

Where Δt is time interval between nth and (n+1)th spike and τ is the time constant of recovery of the synaptic resource and U is the fraction of resources used per action potential.

1. Now I made two files for APMA with different names one for intra-cortical region (which need synaptic depression addition) and other for thalamocortical (normal) connections. Is it right way or single AMPA file can calculate both currents (simple synaptic current and current with synaptic depression).

2. How can I add synaptic depression D in equation? I am not expert in NEURON. Is it possible to multiply D in BREAKPOINT block like mgblock in NMDA receptor or there is some other method? How can we calculate time between two spikes(nth and (n+1)th spike)?Would you suggest some project or code, which help me.

I will wait for your kind reply.