Sacral dorsal horn neurone activity during micturition in the cat
Bibliographic record
Abstract
The excitability of two groups of neurones located in different parts of the sacral spinal cord were examined during micturition in decerebrate adult cats. One group of cells, characterized by their activation by pudendal cutaneous afferents, was located in the dorsal commissure of the first and second sacral spinal segments. The second group, located in the dorsal horn of the first sacral spinal segment, was excited by group II muscle and cutaneous afferents. Micturition was evoked by distension of the urinary bladder or by electrical stimulation of the pontine micturition centre. Tonic firing was induced in the neurones by ejection of DL-homocysteic acid from the recording extracellular micropipette. The instantaneous firing frequency of 11/17 sacral dorsal grey commissure neurones was decreased from 7 to 100 % during micturition, and on average was about half of the prevoid firing frequency. It is hypothesized that these sacral neurones are interposed in polysynaptic excitatory pathways from sacral perineal afferents to sphincter motoneurones and that they are subject to direct postsynaptic inhibition during micturition. One other cell showed no change in firing during micturition, two displayed complex patterns of modulation, while 3/17 of the dorsal grey commissure neurones increased their firing rate 30 to 1000 % during micturition. It is hypothesized that the excited neurones may be part of the inhibitory pathways mediating postsynaptic inhibition of sphincter motoneurones or sacral primary afferent depolarization during micturition. Alternatively, they may be part of the excitatory urethral-bladder reflex circuitry. A small (5-15 %) but significant decrease in firing was observed in 4/5 of the group II rostral sacral neurones examined; the firing of a fifth neurone was unchanged. The depression of group II neurones may serve to suppress unwanted hindlimb reflexes that could disrupt micturition.
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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 | 0.000 | 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) | 0.001 | 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".