User`s guide

8 MATLAB Code Traceability
8-12
Simulate Model and View Results
Simulate slvnvdemo_synaptic_transmission model. Check Scope for results. The six plots
are:
• externally injected electrical current pulse,
• injection-stimulated intracellular voltage spiking of the first neuron,
• post-synaptic current generated in the second neuron,
• synaptically stimulated activity of the second neuron,
• post-synaptic current generated in the third neuron,
• synaptically stimulated activity of the third neuron.
Observe regular spiking of the upstream neuron (plot 2) while stimulation pulse is
applied (plot 1). Synaptically induced current in downstream neuron (plot 3) skips some
action potentials of the upstream neuron due to short-term neurotransmitter depletion
modeled as a temporary turn-off period in Synaptic current function. Downstream
neuron is seen to, sometimes, integrate more than one synaptic input to produce a spike
(plot 4). The third neuron integrates synaptic inputs from the second neuron (plot 5) and
spikes at a later time (plot 6). With our default parameter values, the third neuron may
spike 1 or more times, depending on intentionally introduced random noise in the model.
We assign same parameter values for all three neurons and both synapses. Traceability
linking is used to justify parameter values and implementation.
sim('slvnvdemo_synaptic_transmission');
### Successfully updated the model reference SIM target for model: slvnvdemo_neuron
Navigate Between Simulink and Standalone MATLAB Files
The slvnvdemo_synaptic_transmission model runs an external script to load required
parameter values into workspace. MATLAB code linking allows you to trace from a
dependent block in Simulink, not only to a script file but to the specific line that defines a
value used in simulation.
Locate the Stimulation pulse block in the model. Right-click the block and select
Requirements Traceability > 1. "I_inj = 2e-11; % 20 pA" to follow the link and view
the relevant highlighted region in the MATLAB code file. Notice the mismatched value so
easily detected via Traceability link. Right-click another highlighted line in the MATLAB