Effects of repeated morphine on ultrasonic vocalizations in adult rats: increased 50-kHz call rate and altered subtype profile.
Rationale: Adult rat 50-kHz vocalizations have been proposed to indicate a positive affective state, putatively revealed by a predominance of trill calls over flat calls. However, short-term exposure to non-sedative doses of the euphorigen morphine suppresses calling, with no discernible shift in tr...
| Publicado en: | Psychopharmacology Vol. 234; no. 1; pp. 155 - 166 |
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| Autores principales: | , , , |
| Formato: | Journal Article |
| Publicado: |
Springer Nature
Jan2017
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=120505578&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 120505578 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00333158 EJD jtl: Psychopharmacology issn: 00333158 maglogo: N pubinfo: dt: Jan2017 vid: 234 iid: 1 pid: 237 pub: Springer Nature place: New York, New York artinfo: ui: 120505578 144123110 10.1007/s00213-016-4449-9 120505578 ppf: 155 ppct: 11 formats: fmt: @attributes: type: P tig: atl: Effects of repeated morphine on ultrasonic vocalizations in adult rats: increased 50-kHz call rate and altered subtype profile. aug: au: Best, Laura Zhao, Leah Scardochio, Tina Clarke, Paul affil: Department of Pharmacology and Therapeutics , McGill University , McIntyre Medical Building Rm. 1320, 3655 Promenade Sir William Osler Montreal Quebec H3G 1Y6 Canada sug: ab: Rationale: Adult rat 50-kHz vocalizations have been proposed to indicate a positive affective state, putatively revealed by a predominance of trill calls over flat calls. However, short-term exposure to non-sedative doses of the euphorigen morphine suppresses calling, with no discernible shift in trill or flat call prevalence. Objectives: This study aimed to determine whether morphine acutely increases 50-kHz call rates or alters the relative prevalence of trill or flat calls, after long-term morphine exposure or acute pharmacological pretreatment. Methods: Experiment 1 comprised 10 once-daily tests, alternating between saline and morphine, 1 mg/kg SC, followed by dose-response testing (0, 0.3, 1, and 3 mg/kg). Experiment 2 was similar but included additional testing with morphine in combination with the antinausea drug ondansetron or the peripheral opioid antagonist methylnaltrexone. In experiment 3, morphine was again combined with ondansetron or methylnaltrexone but in rats that were initially drug naïve. Results: In animals that were initially drug naïve, morphine tended to suppress calling and did not alter the 50-kHz call subtype profile. In morphine-experienced rats, morphine acutely increased the 50-kHz call rate and promoted trills over flat calls; short calls were also inhibited. Neither ondansetron nor methylnaltrexone detectably altered any effect of morphine on calling, nor did these two drugs affect 50-kHz calling when given alone. Conclusions: With chronic exposure, morphine acutely enhances 50-kHz calling and differentially promotes trill calls, mainly at the expense of flat calls. These effects appear consistent with a positive affect interpretation of 50-kHz vocalizations. pubtype: Academic Journal doctype: Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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