Tickle contagion in the rat somatosensory cortex

Shaping behaviors through social experience and their proposed sensitivity to stress

Mammals have evolved with a range of innate drives, such as thirst and hunger, that promote motivated behaviors to ensure survival. A drive for social engagement promotes social interaction and bond formation. While a stable social environment maintains the opportunity for resource sharing and protection, an additional benefit is provided by the social transmission of information. Social experiences, and information obtained from conspecifics, can be used to learn about threats and opportunities in the environment. This review examines the primary forms of social learning and how they can shape behavior. Additionally, while there is much known about the effects of stress on learning and memory, there is much less known about its effects on social learning and memory. This review will therefore dissect the major factors that contribute to social learning and propose how stress may impact these factors. This may serve as a way to formulate new hypotheses about how stress might impact social learning and the effects of social experiences on behavior.

The complex affective and cognitive capacities of rats

For several decades, although studies of rat physiology and behavior have abounded, research on rat emotions has been limited in scope to fear, anxiety, and pain. Converging evidence for the capacity of many species to share others' affective states has emerged, sparking interest in the empathic capacities of rats. Recent research has demonstrated that rats are a highly cooperative species and are motivated by others' distress to prosocial actions, such as opening a door or pulling a chain to release trapped conspecifics. Studies of rat affect, cognition, and neural function provide compelling evidence that rats have some capacity to represent others' needs, to instrumentally act to improve their well-being, and are thus capable of forms of targeted helping. Rats' complex abilities raise the importance of integrating new measures of rat well-being into scientific research.

Cheerful tails: Delving into positive emotional contagion

This review delves into the phenomenon of positive emotional contagion (PEC) in rodents, an area that remains relatively understudied compared to the well-explored realm of negative emotions such as fear or pain. Rodents exhibit clear preferences for individuals expressing positive emotions over neutral counterparts, underscoring the importance of detecting and responding to positive emotional signals from others. We thoroughly examine the adaptive function of PEC, highlighting its pivotal role in social learning and environmental adaptation. The developmental aspect of the ability to interpret positive emotions is explored, intricately linked to maternal care and social interactions, with oxytocin playing a central role in these processes. We discuss the potential involvement of the reward system and draw attention to persisting gaps in our understanding of the neural mechanisms governing PEC. Presenting a comprehensive overview of the existing literature, we focus on food-related protocols such as the Social Transmission of Food Preferences paradigm and tickling behaviour. Our review emphasizes the pressing need for further research to address lingering questions and advance our comprehension of positive emotional contagion.

Emotional contagion in rodents: A comprehensive exploration of mechanisms and multimodal perspectives

Emotional contagion, a fundamental aspect of empathy, is an automatic and unconscious process in which individuals mimic and synchronize with the emotions of others. Extensively studied in rodents, this phenomenon is mediated through a range of sensory pathways, each contributing distinct insights. The olfactory pathway, marked by two types of pheromones modulated by oxytocin, plays a crucial role in transmitting emotional states. The auditory pathway, involving both squeaks and specific ultrasonic vocalizations, correlates with various emotional states and is essential for expression and communication in rodents. The visual pathway, though less relied upon, encompasses observational motions and facial expressions. The tactile pathway, a more recent focus, underscores the significance of physical interactions such as allogrooming and socio-affective touch in modulating emotional states. This comprehensive review not only highlights plausible neural mechanisms but also poses key questions for future research. It underscores the complexity of multimodal integration in emotional contagion, offering valuable insights for human psychology, neuroscience, animal welfare, and the burgeoning field of animal-human-AI interactions, thereby contributing to the development of a more empathetic intelligent future.

Effect of lite touch on the anxiety of low-risk pregnant women in the latent phase of childbirth: a randomized controlled trial

Introduction

Women with perinatal anxiety have reduced coping capacity during labor, which affects labor progress and increases the likelihood of a cesarean section. Several non-pharmacological interventions for anxiety during childbirth are available. This study used the "lite touch" method, a non-pharmacological intervention based on physiological responses and obstetric clinical experience in women. We aimed to evaluate whether lite touch could relieve perinatal anxiety and investigate the effect of light skin stroking on the maternal hormones, catecholamine, and cortisol.

Methods

This randomized clinical trial involved women with low-risk singleton pregnancies at full term or near term. Eligible pregnant women who were latent and did not undergo epidural anesthesia were randomized into two groups. Participants in the intervention group underwent routine prenatal care, including lite touch, whereas the control group underwent routine prenatal care alone. Demographic data were collected through a questionnaire. Labor anxiety was assessed using the State Anxiety Inventory, and saliva was collected before and after the intervention. Changes in saliva cortisol and catecholamine levels were analyzed using a double-antibody sandwich enzyme-linked immunosorbent assay.

Results

In total, 83 participants were included, with 43 and 40 in the intervention and control groups, respectively. In the intervention group, pre-intervention anxiety scores were significantly lower (p < 0.01) than post-intervention anxiety scores, whereas the control group showed no difference in anxiety scores before and after intervention (p > 0.05). Cortisol and catecholamine levels in saliva were significantly lower in the intervention group than in the control group after the intervention (p < 0.01).

Discussion

Lite touch can reduce the latent anxiety state of low-risk pregnant women, thereby maintaining in vivo stability and facilitating labor.

Clinical trial registration

https://www.chictr.org.cn/aboutEN.html, ChiCTR2300070905, Retrospectively Registered Date: April 26, 2023.

Play behavior: Tickle and play in the periaqueductal gray

A new study has identified the periaqueductal gray as an important brain region for play and tickle behavior in rats.

Sharing Positive Affective States Amongst Rodents

Group living is thought to benefit from the ability to empathize with others. Much attention has been paid to empathy for the pain of others as an inhibitor of aggression. Empathizing with the positive affect of others has received less attention although it could promote helping by making it vicariously rewarding. Here, we review this latter, nascent literature to show that three components of the ability to empathize with positive emotions are already present in rodents, namely, the ability to perceive, share, and prefer actions that promote positive emotional states of conspecifics. While it has often been argued that empathy evolved as a motivation to care for others, we argue that these tendencies may have selfish benefits that could have stabilized their evolution: approaching others in a positive state can provide information about the source of valuable resources; becoming calmer and optimistic around animals in a calm or positive mood can help adapt to the socially sensed safety level in the environment; and preferring actions also benefiting others can optimize foraging, reduce aggression, and trigger reciprocity. Together, these findings illustrate an emerging field shedding light on the emotional world of rodents and on the biology and evolution of our ability to cooperate in groups.

Protocol for precise signal synchronization of electrophysiology, videography, and audio recordings using a custom-made pulse generator

Precise signal synchronization is vital for accurate analysis in systems neuroscience. Here, we present a protocol for synchronizing electrophysiology, videography, and audio recordings using a custom-made pulse generator. We describe steps for building the pulse generator, installing software, connecting devices, and running experimental sessions. We then detail signal analysis, temporal alignment, and duration normalization. This protocol offers flexibility and cost-effectiveness, addressing limited shared knowledge and providing a solution for signal synchronization in various experimental setups.