From 2f3cb4855ae17ab12c49683097da1f5c090af79d Mon Sep 17 00:00:00 2001 From: ocrampal Date: Fri, 5 Jun 2026 13:08:48 +0200 Subject: [PATCH] Update 2026-06-04-modulation-of-future-behavior.md --- ...026-06-04-modulation-of-future-behavior.md | 26 ++++++++++++++----- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/elements/astrocyte/appunti/2026-06-04-modulation-of-future-behavior.md b/elements/astrocyte/appunti/2026-06-04-modulation-of-future-behavior.md index 7279164..fecca97 100644 --- a/elements/astrocyte/appunti/2026-06-04-modulation-of-future-behavior.md +++ b/elements/astrocyte/appunti/2026-06-04-modulation-of-future-behavior.md @@ -8,7 +8,19 @@ Description of the pseudocode. ## Global state: what each compartment tracks -The three compartments maintain distinct but coupled state variables across three time horizons. At the fast scale, the presynapse tracks residual calcium and its readily-releasable vesicle pool — both of which encode the very recent history of firing. The postsynapse tracks membrane voltage and the amplitude and speed of its calcium rise, which together encode the instruction for future change. The astrocyte tracks glutamate concentration both inside and outside the cleft, its own local and global calcium state, and its fuel output. At the intermediate scale, the shared signal layer tracks whether the mGluR overflow sensors have fired, and whether the neuromodulatory context gate has been set — specifically whether PKA has primed the AMPA insertion machinery, silenced the forgetting phosphatase, and enabled gene expression in the nucleus. At the slow scale, all three compartments track their own physical architecture: the postsynapse its receptor count and spine size, the presynapse its docking slot count and vesicle channel clustering, and the astrocyte its wall distance from the synapse, its matrix density, and its baseline co-agonist supply. +The three compartments maintain distinct but coupled state variables across three time horizons. + +At the fast scale: +- the presynapse tracks residual calcium and its readily-releasable vesicle pool — both of which encode the very recent history of firing. +- the postsynapse tracks membrane voltage and the amplitude and speed of its calcium rise, which together encode the instruction for future change. +- the astrocyte tracks glutamate concentration both inside and outside the cleft, its own local and global calcium state, and its fuel output. + +At the intermediate scale, the shared signal layer tracks whether the mGluR overflow sensors have fired, and whether the neuromodulatory context gate has been set — specifically whether PKA has primed the AMPA insertion machinery, silenced the forgetting phosphatase, and enabled gene expression in the nucleus. + +At the slow scale, all three compartments track their own physical architecture: +- the postsynapse its receptor count and spine size +- the presynapse its docking slot count and vesicle channel clustering +- the astrocyte its wall distance from the synapse, its matrix density, and its baseline co-agonist supply. ## Fast scale: what happens spike by spike @@ -96,12 +108,12 @@ glutamate_clearance_rate // EAAT transporter density function fire_action_potential(input_freq): #### Presynapse: launch wavefront - pre_Ca_residual += spike_influx(input_freq) - pre_Ca_residual *= decay(τ ≈ 100ms) // fades unless spikes keep arriving - vesicle_release_prob *= facilitation(pre_Ca_residual) - released_vesicles = binomial(RRP_pool, vesicle_release_prob) - glutamate_cleft = released_vesicles × quantal_content - RRP_pool -= released_vesicles +pre_Ca_residual += spike_influx(input_freq) +pre_Ca_residual *= decay(τ ≈ 100ms) // fades unless spikes keep arriving +vesicle_release_prob *= facilitation(pre_Ca_residual) +released_vesicles = binomial(RRP_pool, vesicle_release_prob) +glutamate_cleft = released_vesicles × quantal_content +RRP_pool -= released_vesicles #### Astrocyte: overflow sensing and co-agonist release glutamate_spillover = extrasynaptic_diffusion(glutamate_cleft)