50-kHz vocalization subtypes emitted by male rats anticipating a sexual partner: Lack of effect of amphetamine withdrawal
Bibliographic record
Abstract
The sucrose preference test is the primary measure of anhedonia in rat models of depression, but it does not specifically assess anticipatory anhedonia, a deficit commonly observed in patients. Anticipatory 50-kHz ultrasonic vocalizations (USVs) may offer a more translationally relevant affective measure, yet the subtypes linked to reward anticipation and their alteration in depression models remain poorly characterized. The present study investigated whether certain USV measures (i.e., 50-kHz call rate, call subtype prevalence) were modified in male rats while they anticipated access to a sexually-receptive female partner vs. no partner. The study also examined whether withdrawal from a chronic amphetamine regimen (2 mg/kg IP, once daily for 14 days), intended to induce a depressive-like state, would inhibit the anticipation-associated changes in USV measures, and modify performance in conventional measures of depressive-like state (sucrose preference test, forced swim test). However, in contrast to previous reports, no behavioural signs of withdrawal were observed. Independent of amphetamine history, male rats anticipating a sexual partner emitted more 50-kHz calls, with a preferential increase in two rare 50-kHz call subtypes: split and composite calls. Our findings support the notion that subtypes other than the predominantly studied “flat” and “trill” can potentially serve as markers of affect. In particular, split and composite calls may provide novel translationally relevant measures of anticipatory anhedonia, but they need to be evaluated in other rat models of depression. • Male rats awaiting access to a sexually-receptive female emitted many 50-kHz calls. • During anticipation, split and composite call subtypes preferentially increased. • Withdrawal from chronic amphetamine did not alter our 50-kHz related measures. • Amphetamine withdrawal did not appear to elicit 22-kHz vocalizations.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 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".