Progressive elevations in AMPA and GABA<sub>A</sub> receptor levels in deafferented somatosensory cortex
Bibliographic record
Abstract
Restricted receptive fields (RFs), a hallmark of mature sensory systems, are actively maintained by a balance between ascending excitation and local inhibition in the cortex. Deafferentation disrupts this balance, allowing a sequence of changes in neuronal response properties that culminate in the reorganization of cortical RFs. To explore the molecular basis of deafferentation-induced RF reorganization, we tracked changes in AMPA receptor (AMPAR), NMDA receptor (NMDAR) and GABAA receptor (GABAAR) levels in the deafferented somatosensory cortex of adult raccoons following single-digit amputation. In synaptoneurosomes prepared from deafferented cortex, we observe a significant increase in AMPARs, but no change in NMDARs, 1-9 days post-deafferentation, coincident with the appearance of new excitatory inputs and enlarged RFs. We observe a significant increase in GABAARs 2-7 weeks post-deafferentation, coincident with a return of inhibitory input and shrinking RFs. These experience-dependent changes in the levels of the major cortical ionotropic receptors were transient, returning to pre-experimental baseline by > or = 17 weeks post-deafferentation, when RFs return to original size, but are remapped to different loci. This suggests that deafferentation-induced cortical reorganization may be generated by activity-dependent potentiation of weak excitatory synapses, followed by an increase in the strength of inhibitory synapses, resulting in finely tuned, remapped cortical RFs.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".