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name: synapses-and-inputs description: "Define Brian2 2.9.0 synaptic connectivity, event pathways, delays, plasticity, and explicit or stochastic input sources." disable-model-invocation: true metadata: disco-role: operating license: NOASSERTION

Synapses and inputs

Use this route when the task connects spike-producing groups, applies synaptic code, configures delays or plasticity, or supplies Poisson, timed, or explicit spike input in Brian2 2.9.0. The route is deliberately workflow-oriented: first define the source/target and synaptic equations, then create connections, assign existing synapse state, and only then run and inspect event effects.

Route map

• API signatures, indexing, pathway names, and input-class boundaries: api-reference.md
• End-to-end construction, timing, replay, and validation recipes: workflows.md
• Conditional/probabilistic connectivity, event-driven traces, STDP, and summed variables: connectivity-and-plasticity.md
• Install/import, optional dependency, data/configuration, API misuse, timing, and workflow recovery: troubleshooting.md
• Run a tiny deterministic connectivity and delayed-spike assertion: connectivity_smoke.py

Operating contract

1. Keep neuron equation semantics, units, thresholds, resets, and state-updater choice with modeling and units-and-equations. This route consumes a valid spike source and target variable.
2. A Synapses constructor defines model/pathways; it does not create synapses. Call connect(...) before indexing or assigning synaptic arrays.
3. Use explicit _pre/_post suffixes when a name could be ambiguous. Assign w, delay, and other synapse state after the relevant connections exist.
4. Treat event-driven variables as values updated at event times, not as continuously observable traces. Ensure their dependencies remain compatible with event-driven integration.
5. Choose PoissonGroup when individual spikes matter, PoissonInput when only aggregate independent input matters, SpikeGeneratorGroup for reproducible event schedules, and TimedArray for sampled time functions.
6. Validate units, dt/delay alignment, event binning, and output timing with a small fixture before scaling. Monitor analysis belongs to recording; device and standalone restrictions belong to code-generation.

The bundled smoke script is read-only with respect to the repository and uses only a tiny in-memory runtime simulation; it does not download data or run native repository tests.