tsodyks2_synapse

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tsodyks2_synapse#

class brainpy.state.tsodyks2_synapse(*args, **kwargs)#

Tsodyks (2-variable) short-term-plasticity synapse spec.

Parameters:

  • weight (ArrayLike or Quantity, optional) – Per-edge weight (pA; bare numbers interpreted as pA). Default 1.0 pA.

  • delay (Quantity, optional) – Homogeneous axonal delay (> 0). Default 1.0 ms.

  • receptor_type (int, optional) – Postsynaptic receptor port (>= 0). Default 0.

  • U (float, optional) – Baseline utilization, in [0, 1]. Default 0.5.

  • u (float, optional) – Initial utilization, in [0, 1]. Defaults to U. Setting U does not implicitly change u.

  • x (float, optional) – Initial available-resource fraction (not range-checked). Default 1.0.

  • tau_rec (Quantity, optional) – Recovery constant (> 0). Default 800.0 ms.

  • tau_fac (Quantity, optional) – Facilitation constant (>= 0; exactly 0 resets u to U on every non-first spike). Default 0.0 ms.

Notes

t_lastspike initialises to -1.0; the first spike skips the decay (delivering x_init*u_init*weight). tau_fac == 0 is matched by exact floating-point equality (matching NEST), unlike quantal_stp_synapse’s < 1e-10 threshold.

References

Examples

>>> from brainpy.state import tsodyks2_synapse
>>> s = tsodyks2_synapse(U=0.5)
>>> s.edge_state_init()['t_lastspike']
-1.0
>>> s.edge_state_init()['u']
0.5
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