The neural and neurochemical control of spermathecal contractions in the locust, Locusta migratoria
Bibliographic record
Abstract
The spermathecal muscle of Locusta migratoria receives bilateral innervation from at least three nerves which originate from the VIIIth (terminal) abdominal ganglion. The receptaculum seminis nerve innervates the anterior portion of the spermatheca, while the ductus seminalis aperture nerve and N2B4 innervate the posterior portion. Retrograde Neurobiotin and cobalt lysine fills of the receptaculum seminis and ductus seminalis aperture nerve have associated each nerve with bilaterally situated motoneurons in the terminal abdominal ganglion. Both nerves were also associated with dorsal unpaired median (DUM) neurons situated in both the VIIth and terminal abdominal ganglia. Axons from sensory cells, identified in the lateral walls of the genital chamber, were also found to project to the terminal abdominal ganglion. Mechanical stimulation of the genital chamber sensory cells modified the motor activity going to the spermatheca which resulted in altered spermathecal contractions. It is theorized that during oviposition this neural loop is activated by an egg in the genital chamber and is involved in spermatozoa deposition. FMRFamide-related peptides (FaRPs), octopamine and serotonin were associated with the spermathecal muscle using immunohistochemistry, in addition to radioimmunoassay and high performance liquid chromatography (HPLC) coupled to electrochemical detection. The FaRPs which elicited dose-dependent physiological effects included FMRFamide, ADVGHVFLRFamide and SchistoFLRFamide (PDVDHVFLRFamide). FMRFamide increased the amplitude of neurally-evoked spermathecal contractions, while SchistoFLRFamide and ADVGHVFLRFamide had an inhibitory effect. Evidence suggests that the associated FaRP(s) are delivered to the spermatheca from the central nervous system. Octopamine elicited a dose-dependent stimulatory effect on both spontaneous and neurally-evoked spermathecal contractions. This octopamine-induced response was partially inhibited by SchistoFLRFamide. Octopaminergic DUM neurons, situated in the VIIth and terminal abdominal ganglion, are believed to be the source of octopamine at the spermatheca. The octopaminergic actions appear to be mediated through a cyclic adenosine 3′, 5′-monophosphate (cyclic AMP) pathway, since octopamine induced dose-dependent increases in spermathecal cyclic AMP levels. Serotonin also had stimulatory effects on both spontaneous and neurally-evoked spermathecal contractions. Results suggest that the serotonin-induced response may, in part, be mediated through the octopaminergic system and the activation of a cyclic AMP pathway. Serotonin is not supplied to the spermatheca from processes exiting the terminal abdominal ganglion.
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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".