Biology subjects

Vielle, C.

Publications and source records attributed to Vielle, C..

3 recordsLinked to original sources

bioRxiv2023

Peer's Presence Reverses Escalated Cocaine Intake In Rats

The immediate social context critically modulates drug consumption. The presence of an unfamiliar conspecific, naive to the drug, at the time of consumption reduces cocaine self-administration in male rats during short-access sessions, as well as drug intake in human cocaine users. The subthalamic nucleus (STN), a brain structure involved in cocaine addiction and limbic processes, has been proposed to mediate such social influence on this limited level of drug intake. Whether this influence extends to escalated drug consumption remains an open question. In this study, we compared the effect of the presence of an unfamiliar peer, naive to cocaine, on cocaine self-administration in rats having been exposed to either short (2h) or long-access sessions (6h). We showed that the presence of the peer drastically reduced both limited and escalated cocaine intake in males, while it had no effect on females during short-access sessions. Assessing the effect of STN photo-inhibition or high frequency (HF) stimulation in male rats, we demonstrated that it had no effect in the absence of the conspecific in short-access sessions, STN photo-manipulation suppressed the influence of the peers presence. Moreover, STN photo-inhibition and HF stimulation decreased drug consumption in long-access sessions, but no additive effect was observed when associated with the peers presence, confirming an overriding effect of STN manipulation. Taken together, these results highlight the potential influence of socially oriented manipulations on cocaine intake and further position the STN as a critical mediator of the effect of social presence on addictive-like behaviors.

neuroscience↗

bioRxiv2021

Peer presence and familiarity as key factors to reduce cocaine intake: an effect mediated by the Subthalamic Nucleus

Stimulant use, including cocaine, often occurs in a social context whose influence is important to understand to decrease intake and reduce associated harms. Given the regulatory role of the subthalamic nucleus (STN) on cocaine intake and emotions, we investigate its role on such influence of social context on cocaine intake. We explored the influence of peer presence and familiarity on the frequency of self-administered cocaine and its neurobiological basis. We first compared cocaine intake in various conditions (alone or with peers with different characteristics: observing or self-administering, familiar or not, cocaine-naive or not, dominant or subordinate) in rats (n=90). The risk of drug consumption was reduced when a peer was present, observing or self-administering as well, and further diminished when the peer was unfamiliar (vs familiar). The presence of a cocaine-naive peer further decreased cocaine consumption. The presence of a non-familiar and drug-naive peer represents thus key conditions to diminish cocaine intake. We tested the effects of STN lesions in these various conditions and also conducted social experiments to validate the role of STN in social cognition. The STN lesion by itself reduced cocaine intake to the level reached in presence of a stranger naive peer and affected social cognition, positioning the STN as one neurobiological substrate of social influence on drug intake. Finally, with a translational research approach, we compared the drug intake in these conditions in human drug users (n=77). This human study confirmed the beneficial effect of social presence, especially of strangers. Our results indirectly support the use of social interventions and harm reduction strategies, in particular supervised consumption rooms for stimulant users.

neuroscience↗

bioRxiv2021

Evidence for a vocal signature in the rat and its reinforcing effects

While the term "language" is used for human and non-human primates, "vocal communication" is rather used for rodents or other species. The main difference is that there is, to date, no evidence for a vocal signature in the well-known 50- and 22-kHz ultrasonic vocalizations (USV) emitted by rats. Here, we show that rats can recognize the identity of the USV emitter since they self-administer preferentially playback of 50-kHz USV emitted by a stranger rat over those emitted by their cage-mate. In a second experiment, we show that the familiarity with the USV emitter also modulate the effect of USV playback during cocaine self-administration, since only stranger, but not familiar, 50-kHz USV decrease drug intake. Finally, to study the neurobiological substrate of those processes, we have tested the effects of the subthalamic nucleus (STN) lesion on these various conditions. STN-lesioned rats did not lever press much for any USV playback, whatever their emotional valence, nor did they seem able to differentiate familiar from stranger peer. Advocating for the existence of a vocal signature in rats, these results highlight the importance of ultrasonic communication in socio-affective influence of behavior, such as the influence of proximal social factors on drug consumption and confirm the role of the subthalamic nucleus on this influence.

animal behavior and cognition↗