Cholinergic and Serotonergic Excitation of Ascending Commissural Neurons in the Thoraco-Lumbar Spinal Cord of the Neonatal Mouse
Bibliographic record
Abstract
Locomotion requires the coordination of the two sides of the spinal cord-a function fulfilled by commissural neurons. Ascending commissural neurons (aCNs) are known to be rhythmically active during locomotion, and mice lacking a population of aCNs display uncoupling between the left and right hemicords during locomotion. Acetylcholine (ACh) applied to the isolated spinal cord commonly produces left-right alternation, with co-contraction of ipsilateral flexor and extensor motoneuron groups. In this study, aCNs were examined in the neonatal mouse spinal cord after retrograde labeling with a fluorescent dextran. The axons of these cells crossed in the ventral commissure with many crossing in the same transverse plane as the cell body. For cells located in lamina VII and VIII, ACh (10-50 microM) depolarized 92% (13/14) of the cells tested. ACh depolarized and increased the excitability of aCNs in the presence of a decrease in input resistance. ACh was without significant effect on afterhyperpolarization amplitude or voltage threshold of action potential initiation. In those cells sensitive to application of ACh, 90% (9/10 cells) were also depolarized by 5HT (10-50 microM). Application of 5HT significantly increased the input resistance of these cells, and this effect was likely responsible for the observed increase in excitability, because significant effects on the afterhyperpolarization and voltage threshold were again not detected. The high proportion of aCNs excited by both ACh and 5HT suggests that direct activation of aCNs by these two neurotransmitters contributes to the production of a bilaterally coordinated locomotor-like rhythm in the isolated spinal cord.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".