Treatment with low doses of nicotine but not alcohol affects social play reward in rats

Abstract

Social play behaviour is a vigorous, highly rewarding activity in young animals. It is thought to facilitate social, cognitive and emotional development, but its underlying neural mechanisms are incompletely understood. Previously, we found that low doses of alcohol and nicotine enhanced social play behaviour in young rats. Using place and operant conditioning setups to assess the pleasurable and motivational aspects of social play, we investigated how treatment with nicotine and alcohol affects social play reward. Nicotine-treatment increased the incentive motivational properties of social play as well as the expression of social play itself. Moreover, while nicotine by itself evoked conditioned place preference (CPP), it reduced social play-induced CPP. Alcohol-treatment did not affect the motivation for and expression of social play, nor did it affect social play-induced CPP. The finding that nicotine but not alcohol modulates social play reward increases our understanding of the neural underpinnings of this developmentally important behaviour.

Measuring Play Fighting in Rats: A Multilayered Approach

“…We will focus on two commonly used measures, namely nape contacts or pounces and pins. These configurations occur frequently during playful interactions and can be readily detected, and they can be scored by directly observing the encounters in real time (Achterberg & Vanderschuren, 2020; Achterberg et al., 2014; Panksepp, 1998). Pouncing involves one partner making snout contact with the other partner's nape and touching either side of that contact point with its forepaws (Fig.…”

“…These discriminations at an individual level can be useful in studies where a treated rat is paired with an untreated one (Panksepp, Jalowiec, DeEskinazi, & Bishop, 1985, 1994). As treatments that could affect play directly by altering the specific regulatory mechanisms involved in play or indirectly by altering some mechanisms that have a global effect on social behavior or even an overall effect on activity, these measures of play are often coupled with two others (e.g., Achterberg & Vanderschuren, 2020; Achterberg et al., 2015). These are social exploration, in which a rat sniffs or grooms any part of its partner's body (a measure of general social interest) and nonsocial exploration, in which a rat explores the test cage (a measure of general activity).…”

The rough-and-tumble play of rats as a natural behavior suitable for studying the social brain

“…As the rats in the dyadic paradigm are tested for a fixed duration (5–20 min being most common), the effects on both the overall amount of play, as measured by the number of nape attacks launched, and the style of play, as measured by the frequency of use of the different defensive tactics, can be compared between experimental and control pairs. This level of control is especially important for pharmacological manipulations, as the animals need to be tested when the drug reaches its peak effects on the brain (e.g., Field and Pellis, 1994 ; Achterberg and Vanderschuren, 2020 ). However, the downside to the level of control achieved by the dyadic paradigm is that the rats lose the ability to choose their play partner, as it is the experimenter who selects the partner.…”

Increase in sexual motivation throughout adolescence in the cycling female rat

“…For instance, during sexual interaction, late adolescent females exhibit more social investigation than adult rats and display particular behaviors that resemble juvenile play (Agrati et al., 2018). Play behavior is highly rewarding (Achterberg & Vanderschuren, 2020; Achterberg et al., 2016) and has been previously shown to increase from the juvenile to the mid‐adolescence stage, being maximum between PNDs 32 and 40 and declining to a negligible amount by PND 60 (Panksepp, 1981). Interestingly, some behavioral components are shared between typical play and sexual behaviors: for example, play and sexual solicitations resemble each other (Thor & Holloway, 1984) and a crouching or presentation posture is typically displayed during both types of interactions (Poole & Fish, 1975).…”