Correction to: Differential disruption of conditioned ejaculatory preference in the male rat based on different sensory modalities by micro-infusions of naloxone to the medial preoptic area or ventral tegmental area.

After publication of this paper, the authors determined an error in one of the author names: in PubMed Cionnaith CM should be Mac Cionnaith C.

Differential disruption of conditioned ejaculatory preference in the male rat based on different sensory modalities by micro-infusions of naloxone to the medial preoptic area or ventral tegmental area.

RATIONALE: Male rats trained to associate a neutral odor or rodent jacket on a female with their post-ejaculatory reward state display a preference to ejaculate with females bearing the odor or jacket. This conditioned ejaculatory preference (CEP) can be shifted by systemic administration of the opioid antagonist naloxone (NAL) during training, such that NAL-trained males distribute their ejaculations to females without the cue, relative to saline (SAL)-trained males. OBJECTIVE: The present study examined two brain sites, the medial preoptic area (mPOA) or ventral tegmental area (VTA), where the opioid reward state might be induced. METHODS: Sexually naïve Long-Evans males were implanted with bilateral guide cannula aimed at either site before they underwent multi-ejaculatory conditioning trials at 4-day intervals with sexually receptive females that bore either an almond odor or rodent tethering jacket. Infusions of NAL (1 µl/side) or SAL (1 µl/side) were made prior to each conditioning trial. All males were infused with SAL prior to a final open-field choice test with two sexually receptive females, one scented and the other unscented, or one jacketed and the other unjacketed. RESULTS: Males previously conditioned with SAL in either region showed significant CEP. In contrast, prior infusions of NAL to the mPOA shifted the preference towards the unfamiliar female, whereas prior infusions to the VTA abolished CEP for the odor. Subsequent detection of Fos protein induced by the cue showed that, relative to SAL-treated males, prior experience with NAL in the mPOA suppressed Fos in both the mPOA and VTA, whereas prior experience with NAL in to the VTA suppressed Fos in the VTA alone. CONCLUSIONS: Opioid antagonism in the mPOA produces a state of non-reward whereas in the VTA, it produces a state in which the odor does not acquire incentive properties.

Naloxone disrupts the development of a conditioned ejaculatory preference based on a somatosensory cue in male rats.

Male rats develop a conditioned ejaculatory preference (CEP) toward females bearing an odor or somatosensory cue (rodent jacket) when those stimuli are paired with the postejaculatory reward state. As with a copulatory conditioned place preference, CEP for an odor depends on endogenous opioid transmission after ejaculation. The nonselective opioid receptor antagonist naloxone (NAL) disrupts CEP for an odor cue on female rats when injected systemically to males prior to each conditioning trial. Here, we evaluated whether NAL would disrupt the development of a CEP for the somatosensory cue. Long-Evans males were assigned randomly to two groups and underwent 14 copulatory conditioning trials for 30 min each, spaced every 4 days, and consisting of sequential pairing of a jacket on a sexually receptive female and no jacket on a sexually nonreceptive female. The control group was injected with saline (SAL) in both conditions throughout training, whereas the experimental group was injected with NAL when females were receptive and wore a jacket, and with SAL when they were not receptive and did not wear a jacket. On the final test, all males were injected with SAL and placed into an open field with two sexually receptive females, one with the jacket and the other without the jacket. Control males displayed a significant CEP for females with the jacket on, whereas males injected with NAL during sexually receptive jacket conditions displayed a significant CEP for the nonjacketed female. This study confirms that opioid transmission is necessary for the establishment of a somatosensory CEP. (PsycINFO Database Record (c) 2019 APA, all rights reserved).