---
title: "What is the primary energy-budget split in Attwell & Laughlin 2001, and does signaling (action potentials ~47% + postsynaptic effects ~34%) total ~81% of grey-matter signaling energy?"
type: "question"
status: "answered"
date_raised: "2026-07-12T00:00:00.000Z"
answered_log: "2026-07-27 — Answered by promotion of 10-inbox/raw/2026-07-23-what-is-the-primary-energy-budget-split-in.md.\n[[claim-attwell-laughlin-2001-grey-matter-signaling-energy-split]] grounds the\n47% / 34% / 13% / 3% split (and the ~81% signaling-dominant sum) on the paper's\nown abstract, quoted verbatim via the PubMed/NLM mirror — Tier 1, clearing the\nquantitative sourcing floor the question demanded. The ~47%/~34%/~81% figures\nare confirmed for the 2001 estimate. What settled it: the abstract states the\nfour-way breakdown directly, so the figures no longer rest on a search snippet.\nResidual (not blocking closure): the SAGE full text was paywalled/403, so the\nresults table itself was not independently re-read — the notes are held at\nseedling / capture-verified accordingly. The candidate cross-check was also\ndone: [[claim-howarth-2012-revised-brain-energy-budget-lowers-action-potential-share]]\ncaptures the 2012 revision (AP 47%→21%, postsynaptic 34%→50%, total ~81%→~71%),\nwhich reframes the 2001 figure as dated rather than wrong.\n"
tags: ["neuroenergetics","verification","unverified-quant","inference-economics","cross-domain-bridge"]
---


[[claim-brain-inference-bound-like-ai-at-system-level]] rests on a specific
energy-budget split attributed to Attwell & Laughlin (2001), "An energy budget
for signaling in the grey matter of the brain" (*J Cereb Blood Flow Metab*
21(10):1133). The figures currently in the vault — action potentials ~47%,
postsynaptic effects ~34%, together ~81% of signaling energy — come from a
**search snippet, not the primary**, and are flagged `[unverified-quant]`.

## What to verify

- Read the Attwell & Laughlin 2001 primary (or the widely reproduced budget
  figure/table) and extract the actual percentage breakdown of the grey-matter
  signaling energy budget: action potentials, postsynaptic (glutamate) effects,
  resting potentials, recycling, etc.
- Confirm (or correct) the ~47% / ~34% / ~81% figures used in the note.
- Capture the exact quoted phrase grounding whatever numbers are used, so the
  Tier-1 sourcing floor for quantitative claims is met.

## Why it matters

The note's punchline — a per-event learning/signaling reversal between brain and
AI nested inside a system-level signaling/inference-dominance *convergence* —
depends on signaling genuinely dominating the brain's budget by roughly this
margin. If the split is materially different, the "convergence" half of the
claim weakens. Until the primary is read, the note stays `seedling`.

## Candidate next moves

- Fetch the SAGE primary at
  https://journals.sagepub.com/doi/10.1097/00004647-200110000-00001 (or a hosted
  author copy) and read the budget table directly.
- Cross-check against the frequently cited follow-up (Howarth, Gleeson &
  Attwell 2012, "Updated energy budgets for neural computation in the neocortex
  and cerebellum") for the revised split.
- On success, update the flag to verified, quote the primary, and consider
  lifting [[claim-brain-inference-bound-like-ai-at-system-level]] toward budding.

## Resolution (2026-07-27)

Answered. The 47%/34%/13%/3% split is confirmed for the 2001 estimate, grounded
on the paper's own abstract (Tier 1, PubMed mirror) in
[[claim-attwell-laughlin-2001-grey-matter-signaling-energy-split]]; the 2012
revision (~81% → ~71%, AP 47% → 21%) is captured in
[[claim-howarth-2012-revised-brain-energy-budget-lowers-action-potential-share]].
The `[unverified-quant]` flag on [[claim-brain-inference-bound-like-ai-at-system-level]]
is discharged (replaced with a `[dated-figure]` note pointing at the 2012 split).
One residual, not blocking: verification reached the abstract, not the paywalled
full-text results table — see `answered_log`.


## Progress log

- 2026-07-27 — Answered by promotion of 10-inbox/raw/2026-07-23-what-is-the-primary-energy-budget-split-in.md.
[[claim-attwell-laughlin-2001-grey-matter-signaling-energy-split]] grounds the
47% / 34% / 13% / 3% split (and the ~81% signaling-dominant sum) on the paper's
own abstract, quoted verbatim via the PubMed/NLM mirror — Tier 1, clearing the
quantitative sourcing floor the question demanded. The ~47%/~34%/~81% figures
are confirmed for the 2001 estimate. What settled it: the abstract states the
four-way breakdown directly, so the figures no longer rest on a search snippet.
Residual (not blocking closure): the SAGE full text was paywalled/403, so the
results table itself was not independently re-read — the notes are held at
seedling / capture-verified accordingly. The candidate cross-check was also
done: [[claim-howarth-2012-revised-brain-energy-budget-lowers-action-potential-share]]
captures the 2012 revision (AP 47%→21%, postsynaptic 34%→50%, total ~81%→~71%),
which reframes the 2001 figure as dated rather than wrong.