MesoNet: bipolar event design

positive + negative events without automatically making two whole populations? keep event sign, synapse sign and voltage separate... too many different meanings of “negative” here

experiment: vary membrane time constants, reset rules and adaptive thresholds, then represent positive and negative spike events with distinct effects on downstream neurons. The notes compare this with using separate excitatory and inhibitory populations.

implementation direction: custom events and event-specific synaptic pathways. The sign of an event, sign of a synaptic effect and membrane-voltage value are separate design choices; avoid carrying over the notebook's overly broad statement that LIF models cannot represent negative voltage.

observed issue: balancing the two pathways without excessive oscillation requires tuning; added reset/adaptation mechanisms also add computation.

review questions: what happens when a state crosses each threshold? Are event traces and STDP updates specific to polarity? Specify a minimal one-connection test before interpreting behavior of the full network.

References saved in this journal section

• https://brian2.readthedocs.io/en/latest/resources/tutorials/1-intro-to-brian-neurons.html
• https://brian2.readthedocs.io/en/2.7.1/resources/tutorials/2-intro-to-brian-synapses.html
• https://brian2.readthedocs.io/en/2.7.1/reference/brian2.input.spikegeneratorgroup.SpikeGeneratorGroup.html
• https://www.ncbi.nlm.nih.gov/books/NBK11099/
• https://brian2.readthedocs.io/en/2.6.0/examples/IF_curve_LIF.html

Bipolar neuron trace

Bipolar reset response

Bipolar model code

Bipolar response trace

Bipolar response trace