From ec1010955a160f125a3e008cb406c4cea819d259 Mon Sep 17 00:00:00 2001 From: ocrampal Date: Thu, 4 Jun 2026 10:33:02 +0200 Subject: [PATCH] Update 2026-06-04-modulation-of-future-behavior.md --- .../appunti/2026-06-04-modulation-of-future-behavior.md | 4 ++++ 1 file changed, 4 insertions(+) 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 74f9915..32d591d 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 @@ -1,3 +1,7 @@ +--- +include_toc: true +--- + # Intro The synapse uses three interlocking signal systems to translate present activity into future behavioral bias. Ca²⁺ is the universal event recorder — each compartment reads its concentration dynamics differently (amplitude and speed of rise in the postsynapse, residual accumulation in the presynapse, IP3-triggered waves in the astrocyte), so the same ion encodes distinct instructions depending on where and how it appears. cAMP/PKA is the contextual gate: driven by neuromodulatory broadcast (dopamine, norepinephrine), it doesn't write changes itself but determines whether the Ca²⁺ signal gets committed to permanent structure — by priming AMPA receptor insertion, silencing the LTD phosphatase machinery via DARPP-32, and activating CREB-driven gene expression for structural proteins. mGluRs provide the overflow sensing layer: when glutamate spills beyond the cleft, group II/III mGluRs on the presynapse activate a Gi-mediated autoinhibitory brake, while group I mGluRs on the astrocyte trigger the IP3→Ca²⁺→D-serine cascade that amplifies NMDA coincidence detection — a push-pull architecture that simultaneously throttles excessive release and widens the postsynaptic learning window.