Individual reward-seeking behaviors can predict how mice respond to nicotine in a micro-society, as revealed by a new study published on October 24 in the open-access journal PLOS Biology, led by Philippe Faure from PSL Research University in France and his team.
Each animal has unique traits and preferences that influence their social behavior, survival, and vulnerability to diseases, including addiction. The use of nicotine varies widely between individuals and has been associated with personality characteristics. While these associations have been documented, there is still limited knowledge about the neurophysiological processes that result in different behavioral patterns and how they relate to susceptibility to nicotine.
To explore this issue, Faure and his colleagues carried out research in a semi-natural setting called Souris-City, where they monitored the long-term behavior of individual male mice. This environment featured communal living spaces and a separate testing area where the mice performed a reward-seeking task away from their companions. Within this setup, the mice earned individual access to water by completing a specific task in a T-maze, while their social behavior, daily rhythms, and cognitive actions were monitored over time using various sensors.
The mice developed personalized reward-seeking strategies when making choices between water and sucrose in the testing area, which predicted how they adjusted to the introduction of nicotine as an incentive. Additionally, the behavior profiles established while isolated in the test area were linked to their actions in the social context. Differences in decision-making strategies among individual mice were associated with variations in their personalities and activity levels in the dopamine system. These results imply that adaptations to their environment influence behavioral characteristics and sensitivity to nicotine through their impact on dopaminergic activity during nicotine exposure, which may play a role in addiction risk.
According to the researchers, these findings indicate that animals develop unique foraging strategies based on their complex social surroundings. These strategies are shaped by individual traits and the condition of neural circuits, suggesting that a mouse’s specific strategy can be predictive of its reaction to addictive substances. Overall, the study emphasizes the importance of recognizing individual differences in behavior and the underlying biological mechanisms within addiction research, revealing more intricate relationships between neural activity and behavior compared to the assumption that all mice respond similarly to tasks. The authors believe that utilizing extensive naturalistic environments with automated data collection is a powerful approach for investigating susceptibility to substance abuse. Ultimately, this research could be a stepping stone toward developing more personalized methods for addiction treatment and behavioral interventions.
The authors note, “Our study illustrates how individual variability in reward-seeking behaviors is influenced by social settings and directly affects sensitivity to nicotine.”
