Neurobiology of love

Historical evidence from stimulation and lesion studies in animals and humans demonstrated a close association between the hypothalamus and typical and atypical socioemotional behavior. A central hypothalamic contribution to regulation of socioemotional responses was also provided indirectly by studies on oxytocin and arginine vasopressin. However, a limited number of studies have so far directly investigated the contribution of the hypothalamus in human socioemotional behavior. To reconsider the functional role of the evolutionarily conserved hypothalamic region in regulating human social behavior, here I provide a synthesis of neuroimaging investigations showing that the hypothalamus is involved in multiple and diverse facets of human socioemotional behavior through widespread functional interactions with other cortical and subcortical regions...

Myths, drama, and sacred texts have warned against the fragile nature of human love; the closer the affiliative bond, the quicker it can turn into hatred, suggesting similarities in the neurobiological underpinnings of love and hatred. Here, I offer a theoretical account on the neurobiology of hatred based on our model on the biology of human attachments and its three foundations; the oxytocin system, the "affiliative brain", comprising the neural network sustaining attachment, and biobehavioural synchrony, the process by which humans create a coupled biology through coordinated action...

Huntington's disease (HD) is a fatal neurodegenerative disorder caused by an autosomal dominant trinucleotide (CAG) tandem repeat, resulting in complex motor, psychiatric and cognitive symptoms as well as gastrointestinal disturbances and other peripheral symptoms. There are currently no disease-modifying treatments, and the peripheral pathology of the disorder is not well understood. Emerging evidence suggests that the bi-directional communication pathways between the gut and the brain, including the microbiota-gut-brain axis, can affect motor, psychiatric and cognitive symptoms as well as weight loss and sexual dimorphism seen in HD...

Long-term relationships are essential for the psychological wellbeing of humans and many animals. Positive emotions and affective experiences (e.g., romantic or platonic love) seem to be closely related to the creation and maintenance of social bonds. When relationships are threatened or terminated, other emotions generally considered to be negative can arise (e.g., jealousy or loneliness). Because humans and animals share (to varying degrees) common evolutionary histories, researchers have attempted to explain the evolution of affect and emotion through the comparative approach...

Social relationships are an important driver of health, and inflammation has been proposed as a key neurobiological mechanism to explain this effect. Behavioral researchers have focused on social relationship quality to further explain the association, yet recent research indicates that relationship quality may not be as robust a predictor as previously thought. Here, building on animal models of social bonds and recent theory on close relationships, we instead investigated merely being in the physical presence of one's romantic partner...

Love and fear were forged by the same fundamental evolutionary processes that permitted life on Earth. Both love and fear are deeply interwoven with the adaptive management of stress and disease. Love and fear share common roots and both can play a role in reproduction, survival, perceived safety and wellbeing. This special issue of Comprehensive Psychoneuroendocrinology focuses specifically on the causes and consequences of love from the interactive perspectives of evolution, neurobiology and culture.

Maternal and passionate love are both crucial for reproduction and involve attachment behaviors with high rewards. Neurobiological studies of attachment in animal and human neuroimaging studies have suggested that the coordination of oxytocinergic and vasopressinergic pathways, coupled with the dopaminergic reward system, contribute to the formation and maintenance of maternal and passionate love. In the present study, we carried out a quantitative meta-analysis of human neuroimaging to identify common and dissociable neural substrates associated with maternal and passionate love, using the activation likelihood estimation (ALE) approach...

Children's environments - especially relationships with caregivers - sculpt not only developing brains but also multiple bio-behavioral systems that influence long-term cognitive and socioemotional outcomes, including the ability to empathize with others and interact in prosocial and peaceful ways. This speaks to the importance of investing resources in effective and timely programs that work to enhance early childhood development (ECD) and, by extension, reach communities at-scale. Given the limited resources currently devoted to ECD services, and the devastating impact of COVID-19 on children and communities, there is a clear need to spur government leaders and policymakers to further invest in ECD and related issues including gender and racial equity...

The process of dog domestication likely involved at least two functional stages. The initial stage occurred when subpopulations of wolves became synanthropes, benefiting from life nearby or in human environments. The second phase was characterized by the evolution of novel forms of interspecific cooperation and social relationships between humans and dogs. Here, we discuss possible roles of the oxytocin system across these functional stages of domestication. We hypothesize that in early domestication, oxytocin played important roles in attenuating fear and stress associated with human contact...

In social species such as humans, non-human primates, and even many rodent species, social interaction and the maintenance of social bonds are necessary for mental and physical health and wellbeing. In humans, perceived isolation, or loneliness, is not only characterized by physical isolation from peers or loved ones, but also involves negative perceptions about social interactions and connectedness that reinforce the feelings of isolation and anxiety. As a complex behavioral state, it is no surprise that loneliness and isolation are associated with dysfunction within the ventral striatum and the limbic system - brain regions that regulate motivation and stress responsiveness, respectively...

This essay discusses sentient robot (SR) research through the lens of suffering. First three kinds of suffering are considered: physical, psychological, and existential. Physical pain is shown to be primarily subjective, and distinctive psychological and existential sufferings probably do exist, which are neither reducible to neurobiological events, nor replicable through algorithms. The current stage of SR research is then reviewed. Many creative proposals are presented, together with some philosophical and technical challenges posed by other scholars...

Sexual needs and sexuality in older adults continues to be a neglected area of clinical intervention, particularly in longer term care settings. This is often due to older adults in long term care beds presenting with increased frailty, and often with significant neurocognitive disorders, making it difficult for care staff to evaluate the capacity of an older adult resident to participate in sexual activities or a sexual relationship. Talking about sexuality, intimacy and sexual health can be embarrassing at any age and sex is often still considered taboo for people who live in care homes...

In her book, A Room of One's Own, the famous author Virginia Woolf writes "One cannot think well, love well, sleep well if one has not dined well". This is true. All animals need to forage for food and consume specific nutrients to maintain their physiological homeostasis, maximize their fitness and their reproduction. After decades of research in humans and many model organisms, we now know that our brain is one of the key players that control what, when, and how much we eat. In this review, we discuss the recent literature on neural control of food intake behaviors in mice and flies with the view that these two model organisms complement one another in efforts to uncover conserved principles brains use to regulate energy metabolism and food ingestion...

Category learning groups stimuli according to similarity or function. This involves finding and attending to stimulus features that reliably inform category membership. Although many of the neural mechanisms underlying categorization remain elusive, models of human category learning posit that prefrontal cortex plays a substantial role. Here, we investigated the role of the prelimbic cortex (PL) in rat visual category learning by administering excitotoxic lesions before category training and then evaluating the effects of the lesions with computational modeling...

In these last decades, emotions and feelings, neglected for centuries by experimental sciences, have become the topic of extensive neuroscientific research. Currently, love, the most typically human feeling, can be viewed as the result of different phases (steps), each regulated by evolutionary well-conserved and integrated neural substrates. We have proposed that the early stage, generally called romantic love, is the result of the activation of the brain limbic structures regulating fear/anxiety reactions leading to changes of major neurotransmitters, such as increased monoamine levels and decreased serotonin concentrations...

Since its first characterization in the early 1950s, the role of the polypeptidic nerve growth factor (NGF) in controlling behavior remained elusive. Since the mid-1980s, we undertook a series of experiments aimed at elucidating the biological role(s) played by neurotrophins, particularly NGF, in adult rodents. At the beginning, we concentrated on the submandibular salivary gland of the male mouse, which was known to store massive amount of NGF. We found that under specific stress conditions, the salivary NGF is released in the bloodstream: intermale fighting between isolated males was the first reported context in which salivary NGF was released, thus providing a physiological significance for its presence in the adult, territorial males...

Sickness induced by gastrointestinal malaise or by microbial pathogens is more than a private experience. Sick individuals share their illness within their social environment by communicating their sickness to others. In turn, recipients of the communication respond with appropriate behavioral adaptations. Avoidance of sick individuals and the events associated with their sickness is advantageous for members of the group. However, these responses can conflict with the need for comfort or social support expressed by sick individuals...

In 1975, Colwyn Trevarthen first presented his groundbreaking explorations into the early origins of human intersubjectivity. His influential model dictates that, during intimate and playful spontaneous face-to-face protoconversations, the emotions of both the 2-3-month-old infant and mother are nonverbally communicated, perceived, mutually regulated, and intersubjectively shared. This primordial basic interpersonal interaction is expressed in synchronized rhythmic-turn-taking transactions that promote the intercoordination and awareness of positive brain states in both...

Romantic attachment rejection (RAR) is a highly prevalent phenomenon among young adults. Rejection by a romantic attachment figure can be a painful and incapacitating experience with lasting negative mental health sequelae, yet the underlying neurobiology of RAR is not well characterized. We systematically reviewed functional neuroimaging studies of adult RAR. Four functional magnetic resonance imaging (fMRI) studies that measured participants' responses to real or imagined RAR and met inclusion criteria were evaluated...

While parents have long received guidance on how to raise children, a relatively new element of this involves explicit references to infant brain development, drawing on brain scans and neuroscientific knowledge. Sometimes called 'brain-based parenting', this has been criticised from within sociological and policy circles alike. However, the engagement of parents themselves with neuroscientific concepts is far less researched. Drawing on 22 interviews with parents/carers of children (mostly aged 0-7) living in Scotland, this article examines how they account for their (non-)use of concepts and understandings relating to neuroscience...