Bulbospinal control of spinal cord pathways generating locomotor extensor activities in the cat
Bibliographic record
Abstract
Intracellular recording of lumbosacral motoneurones in the decerebrate and partially spinalized cat injected with nialamide and L-dihydroxyphenylalanine (l-DOPA) was used to investigate the interneuronal convergence of two bulbospinal pathways and of the segmental pathways involved with the generation of extensor activities during locomotion. Deiter's nucleus (DN) or the medial longitudinal fasciculus (MLF) was stimulated in alternation with, and in combination with, stimulation of group I afferents from extensor muscles or of contralateral flexor reflex afferents (coFRA). The evoked polysynaptic EPSPs were recorded in extensor motoneurones when long-latency, long-lasting discharges were evoked by the stimulation of coFRA and when the group I autogenetic inhibition in extensors was reversed to polysynaptic excitation. Spatial facilitation was inferred when the amplitude of the EPSPs evoked by the combined stimuli was notably larger than the algebraic sum of the EPSPs evoked by individual stimulation. Both DN (16 motoneurones) and MLF inputs (8 motoneurones) showed spatial facilitation when preceded by coFRA stimuli and both could reset the rhythm of fictive stepping by triggering a precocious extensor phase. MLF showed spatial facilitation with extensor group I inputs in 69% of trials but DN failed to show spatial facilitation in any cells. These results indicate that DN and MLF project to the coFRA pathways of the extensor half-centre for locomotion and MLF, but not DN, converge on segmental interneurones of the extensor group I pathways. The implications of such convergence patterns on the functional organization of the extensor half-centre are discussed.
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 | 0.001 | 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 | 0.001 | 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".