Oxytocin modulates meta-mood as a function of age and sex

Understanding Cognition, Oxytocin, and Pain in Elders (UCOPE): protocol for a double-blinded cross-over trial in chronic knee osteoarthritis pain

BACKGROUND

Osteoarthritis (OA) is the leading cause of disability among older adults with the knee being the most affected joint. Specifically, there is an urgent need to develop better analgesics for individuals with OA-related pain, since currently used analgesics frequently fail to provide adequate relief or must be discontinued owing to adverse effects. A promising treatment is the neuropeptide oxytocin (OT), which has been shown to play a role in endogenous analgesia with human and animal studies demonstrating anti-nociceptive effects. The primary aims of the study are to examine preliminary analgesic effects of a chronic OT intervention in community-dwelling older individuals with chronic knee osteoarthritis pain.

METHODS

In this article, we describe the rationale and design of the Understanding Cognition, Oxytocin, and Pain in Elders (UCOPE) study, a double-blinded intervention in which 80 participants over 45 years of age with knee osteoarthritis pain will be recruited to participate in a cross-over trial of 4 weeks of intranasal oxytocin or placebo administration. Primary study outcomes include preliminary changes in pain intensity and interference as well as multi-modal assessment batteries including circulating biomarkers and neuroimaging measures. Self-reported and quantitative outcomes will be assessed at baseline, post-intervention periods, and up to a 6-month follow-up period.

DISCUSSION

This study will establish preliminary effectiveness of a novel intervention in middle to older aged adults with knee osteoarthritis pain. Achievement of these aims will provide a rich platform for future intervention research targeting improvements in pain and disability among geriatric populations and will serve as a foundation for a fully powered trial to examine treatment efficacy and potential mechanisms of the proposed intervention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03878589. Registered on March 18th, 2019.

The OXT rs6133010 variant modulates susceptibility to psychiatric symptoms during withdrawal in patients with alcohol dependence

BACKGROUND

Alcohol dependence (AD) confers susceptibility to distressing withdrawal symptoms that often lead to relapse. While neuroadaptation during withdrawal influences symptoms, the genetic factors behind it have not been thoroughly investigated. We utilized propensity score matching and investigated connections between AD, OXT rs6133010, and withdrawal symptoms to address confounding variables. By elucidating the OXT rs6133010-AD interaction, we aim to gain insights into alcohol withdrawal variability and contribute to personalized treatment approaches.

METHODS

A cross-sectional study design was employed involving a total of 389 AD patients and 184 healthy controls who were genotyped for the OXT rs6133010 polymorphism. Psychiatric symptoms were evaluated using standardized scales during early withdrawal. Propensity score matching mitigated age and education differences.

RESULTS

A two-way ANOVA demonstrated a significant AD x OXT rs6133010 interaction effect on hostility and anxiety. Further analysis revealed that the regulatory impact of OXT rs6133010 was exclusively in AD patients. Specifically, AD patients with the AA homozygote showed robust protection against hostility and anxiety. Path analysis unveiled the underlying mechanism of OXT symptom regulation.

CONCLUSION

This study presents novel evidence that OXT rs6133010 specifically modulates psychiatric symptoms in AD. The G allele may heighten hostility and anxiety vulnerability during alcohol withdrawal. These findings emphasize considering environmental factors when studying and utilizing oxytocin therapeutically. Additionally, OXT may not directly act as an anxiolytic but instead regulates anxiety by modulating hostility.

Oxytocin in old age psychiatry: A systematic review of the safety of using intranasal oxytocin in older adults

OBJECTIVES

To examine the literature for evidence of adverse events associated with the use of intranasal oxytocin in older adults (60+).

METHODS

A systematic review was undertaken according to PRISMA guidelines. Peer-reviewed literature was searched for studies involving intranasal oxytocin use in older populations. The Joanna Briggs Institute's (JBI) critical appraisal tool was used to assess the quality of included studies.

RESULTS

The search identified nine randomized controlled trials (RCTs) that investigated the effects of intranasal oxytocin on a total sample size of 331 older participants. Adverse effects associated with oxytocin administration were predominantly mild and varied inconsistently between studies. Compared to placebo intranasal oxytocin was not significantly associated with severe adverse outcomes in doses ranging from 24 to 72 IU after single dose and or repeated doses in the short-term.

CONCLUSION

In a population of older adults, intranasal oxytocin is devoid of serious adverse events. Although this review offers valuable insights, it may not fully reflect the potential adverse events associated with the long-term administration of intranasal oxytocin such as would be expected in its clinical application if approved for the treatment of dementia.

Neuroimaging and behavioral evidence of sex-specific effects of oxytocin on human sociality

Although the social role of oxytocin came to light due to sex-specific interactions such as mother-offspring bonding, current understanding of sex differences in the effects of oxytocin on human sociality is limited because of the predominance of all-male samples. With the increasing inclusion of females in intranasal oxytocin research, it is now possible to explore such patterns. Neuroimaging studies reveal relatively consistent sex-differential effects of oxytocin on the activation of brain regions associated with processing social stimuli - particularly the amygdala. Findings from behavioral research are varied but suggest that oxytocin more often facilitates social cognition and positive social interactions in males, with context-dependent effects in each sex. We discuss potential biological and psychological mechanisms underlying the reported sex differences, and conclude with considerations for future research and clinical applications of oxytocin.

The impact of oxytocin on emotion recognition and trust: Does disordered eating moderate these relationships?

OBJECTIVES

The current study aimed to investigate the impact of oxytocin on emotion recognition, trust, body image, affect, and anxiety and whether eating disorder (ED) symptoms moderated any of these relationships.

METHOD

Participants (n = 149) were female university students, who were randomly allocated to receive in a double-blind nature, a single dose of oxytocin intranasal spray (n = 76) or a placebo (saline) intranasal spray (n = 73). Participants were asked to complete an experimental measure of emotion recognition and an investor task aimed to assess trust.

RESULTS

The oxytocin group exhibited better overall performance on the emotion recognition task (especially with recognising positive emotions), and a decline in state positive affect than the control group at post-intervention. However, these effects were not moderated by ED symptom severity, nor were effects found for state anxiety, negative affect, body image and recognising negative emotions in the emotion recognition task.

CONCLUSION

The current findings contribute to the growing literature on oxytocin, emotion recognition and positive affect and suggest that ED pathology does not moderate these relationships. Future research would benefit from examining the efficacy of an oxytocin intervention using a within-subjects, cross-over design, in those with sub-clinical and clinical EDs, as well as healthy controls.

Single dose intranasal oxytocin administration: Data from healthy younger and older adults

Oxytocin (OT) is a neuropeptide critically involved in social cognition and behavior. Intranasal administration of OT has modulatory effects on both the brain and behavior with potential for therapeutic benefit, especially in individuals with deficits in socioemotional functions. Intranasal OT effects have been well-investigated in younger adults as well as in a variety of clinical populations (e.g., autism, schizophrenia), but there is comparatively less investigation of its function in older adults. To foster more research on OT and aging, the following dataset was made publicly available, which includes data from generally healthy younger (n = 44, age range = 18-31 years [M(SD) = 22.4 (3.0)], 48% female) and older adults (n = 43, age range = 63-81 years [M(SD)= 71.1 (5.3)], 56% female) who self-administered a single dose (24 international units) of either intranasal OT or a placebo (IND 100,860; NCT01823146). The study adopted a randomized, double-blind, between-subject design. The dataset consists of anatomical and functional resting-state neuroimaging scans acquired after nasal spray administration as well as study-specific phenotypic and demographic data. This dataset using both OT administration and neuroimaging is unique in its size and inclusion of both younger and older adults as well as women and men. This data has resulted in published work on OT modulation of cognition, behavior, and neural activation/connectivity. Open access to this data will provide the scientific community with the opportunity to investigate individual differences in the neurocognitive effects of single-dose OT in younger and older adults.

Four-week intranasal oxytocin administration reduces attachment avoidance in older women

The neuropeptide oxytocin (OT) serves as a critical modulator of social cognition and social behavior. Adult attachment is an affiliative process crucial for social interaction across adulthood. Insecure adult attachment comprises two broad dimensions, attachment anxiety and attachment avoidance. Both these dimensions of attachment are currently understudied regarding OT modulation, and especially in older adults. The present study determined the effects of chronic intranasal OT administration on adult attachment in generally healthy older women and men (aged 55-95 years). Embedded in a larger project, participants were randomly assigned to self-administer 24 international units of either OT or a placebo (P) intranasally twice daily for four weeks. The Experiences in Close Relationships Scale assessed adult attachment (anxiety and avoidance) pre- and post-treatment. There was no significant pre- to post-treatment change in attachment avoidance overall, but the treatment x timepoint x sex interaction was significant, in that women (but not men) in the OT (vs. P) group reported decreased attachment avoidance. No comparable effects were observed for attachment anxiety. Results suggest that older women may benefit from chronic intranasal OT treatment by experiencing less attachment avoidance in their adult relationships.

Serum oxytocin correlated with later logical memory in older Japanese women: A 7-year follow-up study

Objectives

This study aimed to investigate the longitudinal relationship between serum oxytocin and logical memory among older adults in rural Japan and clarify sex differences in this relationship.

Measurements

The first survey was conducted from October 2009 to March 2011 (Time 1) and the second from November 2016 to September 2017 (Time 2). The final analysis for Time 1 included 385 participants (median age 75 years, interquartile range [IQR] 70-81 years) and that for Time 2 included 76 participants (median age 80 years, IQR 76-83 years). We assessed cognition, logical memory, and living conditions, and measured serum oxytocin levels. Logical memory was evaluated using the Wechsler Memory Scale-Revised Logical Memory II delayed recall part A (LM II-DR). Serum oxytocin was measured using the enzyme immunoassay method.

Results

The median (IQR) oxytocin level among men (n = 20) was 34 (16-78) pg/mL at Time 1 and 53 (28-140) pg/mL at Time 2. The median (IQR) oxytocin level among women (n = 56) was 117 (35-412) pg/mL at Time 1 and 76 (32-145) pg/mL at Time 2. The median oxytocin level among women at Time 2 was significantly lower than that at Time 1 (p = 0.004). The multivariate analysis showed that for women, LM II-DR score at Time 2 was positively associated with oxytocin level at Time 1 (p = 0.042) and negatively associated with age (p = 0.02).

Conclusions

Our study suggests that maintaining high oxytocin levels in older women may prevent age-related decline in logical memory.

Evaluating the neuropeptide-social cognition link in ageing: the mediating role of basic cognitive skills

The roles of oxytocin (OT) and arginine-vasopressin (AVP) as crucial modulators of social cognition and related behaviours have been extensively addressed in the literature. The involvement of these neuropeptides in social cognition in ageing, however, and a potential mediating effect of basic cognitive capacities on this link, are not well understood. To fill these research gaps, this study assessed associations of plasma OT and AVP levels with dynamic emotion identification accuracy in generally healthy older men (aged 55-95 years) and probed the underlying roles of crystallized and fluid cognition in these associations. Higher plasma OT levels were associated with lower accuracy in dynamic emotion identification, with this negative relationship fully mediated by cognition. For plasma AVP levels, in contrast, there was no association with dynamic emotion identification accuracy. Integrated within existing theoretical accounts, results from this study advance understanding of the neuropeptide-social cognition link in ageing and support basic cognitive capacities as mediators in this association. This article is part of the theme issue 'Interplays between oxytocin and other neuromodulators in shaping complex social behaviours'.

Birth, love, and fear: Physiological networks from pregnancy to parenthood

Pregnancy and childbirth are among the most dramatic physiological and emotional transformations of a lifetime. Despite their central importance to human survival, many gaps remain in our understanding of the temporal progression of and mechanisms underlying the transition to new parenthood. The goal of this paper is to outline the physiological and emotional development of the maternal-infant dyad from late pregnancy to the postpartum period, and to provide a framework to investigate this development using non-invasive timeseries. We focus on the interaction among neuroendocrine, emotional, and autonomic outputs in the context of late pregnancy, parturition, and post-partum. We then propose that coupled dynamics in these outputs can be leveraged to map both physiologic and pathologic pregnancy, parturition, and parenthood. This approach could address gaps in our knowledge and enable early detection or prediction of problems, with both personalized depth and broad population scale.

Age-Related Differences in Amygdala Activation Associated With Face Trustworthiness but No Evidence of Oxytocin Modulation

The amygdala has been shown to be responsive to face trustworthiness. While older adults typically give higher face trustworthiness ratings than young adults, a direct link between amygdala response and age-related differences in face trustworthiness evaluation has not yet been confirmed. Additionally, there is a possible modulatory role of the neuropeptide oxytocin in face trustworthiness evaluation, but the results are mixed and effects unexplored in aging. To address these research gaps, young, and older adults were randomly assigned to oxytocin or placebo self-administration via a nasal spray before rating faces on trustworthiness while undergoing functional magnetic resonance imaging. There was no overall age-group difference in face trustworthiness ratings, but older compared to young participants gave higher trustworthiness ratings to ambivalently untrustworthy-looking faces. In both age groups, lower face trustworthiness ratings were associated with higher left amygdala activity. A comparable negative linear association was observed in right amygdala but only among young participants. Also, in the right amygdala, lower and higher, compared to moderate, face trustworthiness ratings were associated with greater right amygdala activity (i.e., positive quadratic (U-shaped) association) for both age groups. Neither the behavioral nor the brain effects were modulated by a single dose of intranasal oxytocin administration, however. These results suggest dampened response to faces with lower trustworthiness among older compared to young adults, supporting the notion of reduced sensitivity to cues of untrustworthiness in aging. The findings also extend evidence of an age-related positivity effect to the evaluation of face trustworthiness.

Oxytocin Release Increases With Age and Is Associated With Life Satisfaction and Prosocial Behaviors

Helping behaviors and life satisfaction generally increase after middle-age. Identifying the neural substrates of prosocial behaviors in older adults may offer additional insights into these changes over the lifespan. The present study examines the endogenous release of the neuromodulator oxytocin (OT) in participants aged 18-99 and its relationship to prosocial behaviors. OT has been shown to influence trust, altruism, charity, and generosity, yet the effect of age on OT release has not been well-established. Blood samples before and after a video stimulus were obtained from 103 participants in order to examine the impact of OT on prosocial behaviors. We found that OT release following a social prime increased with age (r = 0.49, p = 0.001) and that OT moderated the relationship between age and donations to charity. We tested for robustness by examining three additional prosocial behaviors, money and goods donated to charity during the past year and social-sector volunteering. OT moderated the impact of age on all three prosocial behaviors (ps < 0.05). The analysis also showed that participants' change in OT was positively associated with satisfaction with life (p = 0.04), empathic concern (p = 0.015), dispositional gratitude (p = 0.019), and religious commitment (p = 0.001). Our findings indicate that the neural chemistry that helps sustain social relationships and live a fulfilled life appear to strengthen with age.

Associations between alcohol use and peripheral, genetic, and epigenetic markers of oxytocin in a general sample of young and older adults

INTRODUCTION

Human and nonhuman animal research suggests that greater oxytocin (OT) activity is protective against harmful substance use. Most research on this topic is preclinical, with few studies evaluating the association between substance use and individual differences in the human OT system. The present study sought to fill this gap by evaluating the relationship between alcohol use and multiple biological measures of OT activity in an overall low to moderate-drinking sample.

METHOD

As part of a larger study, generally healthy young (n = 51) and older (n = 53) adults self-reported whether they regularly used alcohol and how much alcohol they consumed per week. Participants also provided blood samples from which peripheral OT, and in an age-heterogeneous subset of participants (n = 56) variation in the oxytocin receptor gene (the OXTR rs53576 polymorphism) and OXTR DNA methylation levels (at cytosine-guanine dinucleotide sites -860, -924, -934), were obtained.

RESULTS

A-allele carriers of the OXTR rs53579 polymorphism were less likely to regularly consume alcohol. Among regular alcohol consumers, number of alcoholic drinks per week was positively associated with peripheral OT in regression models excluding observations of high influence (postdiagnostic models). Number of alcoholic drinks per week was consistently negatively associated with OXTR DNA methylation at site -860; and with OXTR DNA methylation at site -924 in postdiagnostic models.

CONCLUSIONS

The significant associations between alcohol use and individual differences in OT activity support the involvement of the OT system in alcohol use, which most likely reflect the role of OT when alcohol use is under control of its rewarding properties and/or the acute impacts of alcohol on the OT system. Additional research with markers of OT activity and alcohol use, particularly longitudinal, is needed to clarify the bidirectional effects of OT and alcohol use in moderate to harmful drinking and dependence.

Safety and tolerability of chronic intranasal oxytocin in older men: results from a randomized controlled trial

RATIONALE

Most studies evaluating the safety and tolerability of intranasal oxytocin (OT) have not reported consistent adverse events (AEs), but they have largely focused on young men and single-dose administration. Thus, it is unclear whether these findings translate to older individuals and with longer administration periods.

OBJECTIVE

Extending previous work, this study investigated the safety and tolerability of chronic intranasal OT in generally healthy older men.

METHODS

Data were from a randomized, placebo (P)-controlled, double-blind clinical trial evaluating the effects of 4 weeks of self-administered intranasal OT (24 IU twice daily) in older adults with no major physical or cognitive impairments. Heart rate, blood pressure, urine osmolality, and serum metabolic biomarkers were obtained before and at the end of the intervention. AEs were collected during the first 3 weeks and 1 week after cessation of treatment.

RESULTS

Of 103 participants recruited, 95 were randomized and received the intervention (OT = 49, P = 46). OT had no significant impact on cardiovascular, urine, or serum measures. The AEs reported for both treatments were generally mild and few in number, though one participant assigned to OT and two assigned to P dropped out due to AEs. Relative to P, OT did not significantly increase the likelihood of reporting AEs, nor the number or severity of AEs reported.

CONCLUSION

Chronic intranasal OT appears safe and well-tolerated in generally healthy older men. These findings provide support for continued human research on potential benefits of chronic OT in older adult populations.

Sex Differences in the Hypothalamic Oxytocin Pathway to Locus Coeruleus and Augmented Attention with Chemogenetic Activation of Hypothalamic Oxytocin Neurons

The tightly localized noradrenergic neurons (NA) in the locus coeruleus (LC) are well recognized as essential for focused arousal and novelty-oriented responses, while many children with autism spectrum disorder (ASD) exhibit diminished attention, engagement and orienting to exogenous stimuli. This has led to the hypothesis that atypical LC activity may be involved in ASD. Oxytocin (OXT) neurons and receptors are known to play an important role in social behavior, pair bonding and cognitive processes and are under investigation as a potential treatment for ASD. However, little is known about the neurotransmission from hypothalamic paraventricular (PVN) OXT neurons to LC NA neurons. In this study, we test, in male and female rats, whether PVN OXT neurons excite LC neurons, whether oxytocin is released and involved in this neurotransmission, and whether activation of PVN OXT neurons alters novel object recognition. Using "oxytocin sniffer cells" (CHO cells that express the human oxytocin receptor and a Ca indicator) we show that there is release of OXT from hypothalamic PVN OXT fibers in the LC. Optogenetic excitation of PVN OXT fibers excites LC NA neurons by co-release of OXT and glutamate, and this neurotransmission is greater in males than females. In male, but not in female animals, chemogenetic activation of PVN OXT neurons increases attention to novel objects.

Effects of Playing Angklung and Practicing Silence on Emotion, Cognition and Oxytocin Levels in Children: A Preliminary Study

Background

Playing angklung, an Indonesian traditional musical instrument and practicing silence have been shown to exert beneficial effects on emotion and cognition; the mechanism of such an effect possibly involve oxytocin. To date, only a few clinical and biomolecular studies have investigated the effects of playing angklung and practicing silence. This study aimed to examine the effects of playing angklung and practicing silence on human emotion and cognition and on oxytocin levels.

Methods

This experimental study involved 61 Fourth Grade students from Surabaya, East Java, Indonesia. The participants were divided into two groups: the angklung intervention group and silence intervention group. The two interventions were performed for 15 min before the morning classes for 2 months. The control group attended their classes as usual. Clinical parameters, namely, emotion and cognition, as well as the saliva oxytocin levels were measured.

Results

No significant differences were observed among the three groups in terms of concentration and cognitive flexibility. However, changes in oxytocin levels significantly differed among the three groups (P < 0.001) and the oxytocin levels were highest in the silence intervention group.

Conclusion

Practicing silence significantly increased the oxytocin levels, but it did not elicit changes in cognitive function and emotion of the students.

Age and intranasal oxytocin effects on trust-related decisions after breach of trust: Behavioral and brain evidence

Age-related differences in cognition and socioemotional functions, and in associated brain regions, may reduce sensitivity to cues of untrustworthiness, with effects on trust-related decision making and trusting behavior. This study examined age-group differences in brain activity and behavior during a trust game. In this game, participants received "breach-of-trust" feedback after half of the trials. The feedback indicated that only 50% of the monetary investment into their fellow players had resulted in returns. The study also explored the effects of intranasal oxytocin on trust-related decisions in aging, based on suggestions of a modulatory role of oxytocin in response to negative social stimuli and perceptions of trust. Forty-seven younger and 46 older participants self-administered intranasal oxytocin or placebo, in a randomized, double-blind, between-subjects procedure, before they engaged in the trust game while undergoing functional magnetic resonance imaging (fMRI). Younger participants invested less into their game partners after breach-of-trust feedback, while older participants showed no significant difference in their investment after breach-of-trust feedback. Oxytocin did not modulate the behavioral effects. However, after breach-of-trust feedback, older participants in the oxytocin group showed less activity in the left superior temporal gyrus. In contrast, older participants in the placebo group showed more activity in left superior temporal gyrus after breach of trust. The findings may reflect reduced responsiveness to cues of untrustworthiness in older adults. Furthermore, the modulatory effect of oxytocin on left superior temporal gyrus activity among older adults supports the neuropeptide's age-differential role in neural processes in aging, including in the context of trust-related decision making. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Serum Oxytocin Levels and Logical Memory in Older People in Rural Japan

OBJECTIVE

The present study aimed to investigate the relationship between serum oxytocin (OT) and logical memory among older people in rural Japan.

METHODS

This was a cross-sectional study using a survey conducted from October 2009 through March 2011. Most of the study was conducted as part of a national prevalence survey of dementia in Japan. The final sample comprised 385 community-dwelling people aged 65 years or older living in rural Japan. The mean age and standard deviation were 75.7 ± 6.76 years (144 men, mean age 75.0 ± 6.48 years; 241 women, mean age 76.2 ± 6.91 years). The participants underwent screening examinations for a prevalence survey of dementia. The screening examinations were the Mini-Mental State Examination, Clinical Dementia Rating, and "logical memory A" from the Wechsler Memory Scale-Revised (WMSR). We used the WMSR Logical Memory II delayed recall score (LM II-DR) to assess logical memory. Levels of serum OT were obtained using the enzyme immunoassay method.

RESULTS

Serum OT levels were significantly higher among women than men. The present study revealed that serum OT levels were positively associated with LM II-DR in older women living in rural Japan in multiple linear regression analyses.

CONCLUSIONS

The present results suggested a positive correlation between OT and logical memory in older women living in rural Japan.

Chronic oxytocin administration in older men modulates functional connectivity during animacy perception

While aging is associated with social-cognitive change and oxytocin plays a crucial role in social cognition, oxytocin's effects on the social brain in older age remain understudied. To date, no study has examined the effects of chronic intranasal oxytocin administration on brain mechanisms underlying animacy perception in older adults. Using a placebo-controlled, randomized, double-blinded design in generally healthy older men (mean age (SD) = 69(6); n = 17 oxytocin; n = 14 placebo), this study determined the effects of a four-week intranasal oxytocin administration (24 international units/twice a day) on functional MRI (fMRI) during the Heider-Simmel task. This passive-viewing animacy perception paradigm contains video-clips of simple shapes suggesting social interactions (SOCIAL condition) or exhibiting random trajectories (RANDOM condition). While there were no oxytocin-specific effects on brain fMRI activation during the SOCIAL compared to the RANDOM condition, pre-to-post intervention change in the SOCIAL-RANDOM difference in functional connectivity (FC) was higher in the oxytocin compared to the placebo group in a network covering occipital, temporal, and parietal areas, and the superior temporal sulcus, a key structure in animacy perception. These findings suggest oxytocin modulation of circuits involved in action observation and social perception. Follow-up analyses on this network's connections suggested a pre-to-post intervention decrease in the SOCIAL-RANDOM difference in FC among the placebo group, possibly reflecting habituation to repeated exposure to social cues. Chronic oxytocin appeared to counter this process by decreasing FC during the RANDOM and increasing it during the SOCIAL condition. This study advances knowledge about oxytocin intervention mechanisms in the social brain of older adults.

Innovations in Geroscience to enhance mobility in older adults

Aging is the primary risk factor for functional decline; thus, understanding and preventing disability among older adults has emerged as an important public health challenge of the 21st century. The science of gerontology - or geroscience - has the practical purpose of "adding life to the years." The overall goal of geroscience is to increase healthspan, which refers to extending the portion of the lifespan in which the individual experiences enjoyment, satisfaction, and wellness. An important facet of this goal is preserving mobility, defined as the ability to move independently. Despite this clear purpose, this has proven to be a challenging endeavor as mobility and function in later life are influenced by a complex interaction of factors across multiple domains. Moreover, findings over the past decade have highlighted the complexity of walking and how targeting multiple systems, including the brain and sensory organs, as well as the environment in which a person lives, can have a dramatic effect on an older person's mobility and function. For these reasons, behavioral interventions that incorporate complex walking tasks and other activities of daily living appear to be especially helpful for improving mobility function. Other pharmaceutical interventions, such as oxytocin, and complementary and alternative interventions, such as massage therapy, may enhance physical function both through direct effects on biological mechanisms related to mobility, as well as indirectly through modulation of cognitive and socioemotional processes. Thus, the purpose of the present review is to describe evolving interventional approaches to enhance mobility and maintain healthspan in the growing population of older adults in the United States and countries throughout the world. Such interventions are likely to be greatly assisted by technological advances and the widespread adoption of virtual communications during and after the COVID-19 era.

The Role of Intranasal Oxytocin on Social Cognition: An Integrative Human Lifespan Approach

PURPOSE OF REVIEW

This narrative review synthesizes research from the last two decades on the modulatory role of intranasal OT administration (IN-OT) on social cognition in early life, young/middle adulthood, and older adulthood. Advances and knowledge gaps are identified, and future research directions are discussed within an integrative human lifespan framework to guide novel research on IN-OT and social cognition.

RECENT FINDINGS

Current evidence regarding IN-OT modulation of social-cognitive processes, behavior, and related neurocircuitry is mixed, with some studies suggesting benefits (e.g., improved social perception/interactions, emotion processing) depending on contextual (e.g., social stimuli) and interindividual factors (e.g., age, sex, clinical status). Current research, however, is limited by a focus on isolated life phases, males, and select clinical populations as well as a lack of standardized protocols.

SUMMARY

This literature-based reflection proposes that greater generalizability of findings and scientific advancement on social-cognitive modulation via IN-OT require standardized, multi-method, longitudinal, and cross-sequential assessments in well-powered, well-controlled, and representative samples in line with an integrative lifespan approach, which considers development as a lifelong dynamic process involving both change and stability characterized by the interplay between genetic, neurobiological, and socio-behavioral factors.

Tri-Phasic Model ofOxytocin (TRIO): A systematic conceptual review of oxytocin-related ERP research

BACKGROUND

The neuropeptide oxytocin (OT) has been shown to play a role in variety of cognitive and social processes and different hypotheses have been put forth to explain OT's effects on brain and behavior in humans. However, these previous explanatory accounts do not provide information about OT-related temporal modulation in the brain.

OBJECTIVES

This paper systematically reviewed intranasal OT administration studies employing event-related potentials (ERPs) and synthesized the existing evidence into a novel conceptual framework.

METHODS

Empirical studies, published until February 2020 and cited in major databases (EBSCOhost, PubMed, and Web of Science), were examined in accordance with PRISMA guidelines. To be included, studies had to: (i) employ intranasal administration of OT, as the chemical modulator; (ii) measure ERPs; (iii) be peer-reviewed journal articles; (iv) be written in English; and (v) examine human participants.

RESULTS

The search criteria yielded 17 empirical studies. The systematic review resulted in conceptualization of the Tri-Phasic Model ofOxytocin (TRIO), which builds on three processing stages: (i) perception, (ii) selection, and (iii) evaluation. While OT increases attention irrespective of stimuli characteristics in the perception stage, in the selection and evaluation stages, OT acts as a filter to guide attention selectively towards social over non-social stimuli and modulates prosociality/approach motivation associated with social stimuli.

CONCLUSIONS

TRIO offers an empirically-derived conceptual framework that can guide the study of OT-related modulation on attentional processes, starting very early in the processing stream. This novel account furthers theoretical understanding and informs empirical investigation into OT modulation on the brain.

Musculoskeletal Pain and Brain Morphology: Oxytocin's Potential as a Treatment for Chronic Pain in Aging

Chronic pain disproportionately affects older adults, severely impacting quality of life and independent living, with musculoskeletal pain most prevalent. Chronic musculoskeletal pain is associated with specific structural alterations in the brain and interindividual variability in brain structure is likely an important contributor to susceptibility for the development of chronic pain. However, understanding of age-related structural changes in the brain and their associations with chronic musculoskeletal pain is currently limited. Oxytocin (OT), a neuropeptide present in the periphery and central nervous system, has been implicated in pain attenuation. Variation of the endogenous OT system (e.g., OT receptor genotype, blood, saliva, and cerebrospinal fluid OT levels) is associated with morphology in brain regions involved in pain processing and modulation. Intranasal OT administration has been shown to attenuate pain. Yet, studies investigating the efficacy of OT for management of chronic musculoskeletal pain are lacking, including among older individuals who are particularly susceptible to the development of chronic musculoskeletal pain. The goal of this focused narrative review was to synthesize previously parallel lines of work on the relationships between chronic pain, brain morphology, and OT in the context of aging. Based on the existing evidence, we propose that research on the use of intranasal OT administration as an intervention for chronic pain in older adults is needed and constitutes a promising future direction for this field. The paper concludes with suggestions for future research in the emerging field, guided by our proposed Model of Oxytocin's Anagelsic and Brain Structural Effects in Aging.

Plasma oxytocin and vasopressin levels in young and older men and women: Functional relationships with attachment and cognition

A growing literature associates the neuropeptides oxytocin (OT) and arginine vasopressin (AVP) with affiliative and cognitive outcomes. The majority of this work in humans, however, considers these neuropeptides separately. Also, despite evidence that OT and AVP interact with gonadal hormones, still warranted is an examination of sex and age variations in endogenous neuropeptide levels, their interrelations, and their functional relationships with attachment and cognition in humans. This study measured endogenous plasma OT and AVP levels in generally healthy young (18-31 years) and older (63-81 years) men and women to (i) determine levels of and interrelations between OT and AVP; (ii) explore functional relationships with self-reported attachment (attachment anxiety and avoidance) and performance-based cognition (processing speed, verbal memory); and (iii) identify variations in these effects by sex and age. We observed sex- and age-differential patterns of results: Women had higher plasma OT levels than men and older adults had higher plasma AVP levels than young adults. The two neuropeptides were highly negatively intercorrelated across all groups. Functionally, higher AVP levels were associated with greater attachment anxiety and higher OT and lower AVP levels were associated with faster sensorimotor processing speed, with sex and age moderating these effects. This integrated approach identifies variations in endogenous peripheral neuropeptide levels in humans, supporting their sex- and age-specific role as "difference makers" in attachment and cognition.

Chronic oxytocin administration as a tool for investigation and treatment: A cross-disciplinary systematic review

Oxytocin (OT) subserves various physiological, behavioral, and cognitive processes. This paired with the ability to administer OT with minimal and inconsistent side effects has spurred research to explore its therapeutic potential. Findings from single-dose studies indicate that OT administration may be beneficial, at least under certain circumstances. The state of the field, however, is less clear regarding effects from chronic OT administration, which more closely resembles long-term treatment. To address this gap, this review synthesizes existing findings on the use of chronic OT administration in animal and human work. In addition to detailing the effects of chronic OT administration across different functional domains, this review highlights factors that have contributed to mixed findings. Based on this review, a basic framework of interrelated regulatory functions sensitive to chronic OT administration is offered. The paper also identifies future research directions across different contexts, populations, and outcomes, specifically calling for more systematic and standardized research on chronic OT administration in humans to supplement and expand what is currently known from preclinical work.

Oxytocin alters patterns of brain activity and amygdalar connectivity by age during dynamic facial emotion identification

Aging is associated with increased difficulty in facial emotion identification, possibly due to age-related network change. The neuropeptide oxytocin (OT) facilitates emotion identification, but this is understudied in aging. To determine the effects of OT on dynamic facial emotion identification across adulthood, 46 young and 48 older participants self-administered intranasal OT or a placebo in a randomized, double-blind procedure. Older participants were slower and less accurate in identifying emotions. Although there was no behavioral treatment effect, partial least squares analysis supported treatment effects on brain patterns during emotion identification that varied by age and emotion. For young participants, OT altered the processing of sadness and happiness, whereas for older participants, OT only affected the processing of sadness (15.3% covariance, p = 0.004). Furthermore, seed partial least squares analysis showed that older participants in the OT group recruited a large-scale amygdalar network that was positively correlated for anger, fear, and happiness, whereas older participants in the placebo group recruited a smaller, negatively correlated network (7% covariance, p = 0.002). Advancing the literature, these findings show that OT alters brain activity and amygdalar connectivity by age and emotion.

Systemic Inflammation Mediates Age-Related Cognitive Deficits

The association between systemic inflammation and cognitive deficits is well-documented. Further, previous studies have shown that systemic inflammation levels increase with age. The present study took a novel approach by examining the extent to which systemic inflammation levels mediated age-related cognitive decline. Forty-seven young and 46 older generally healthy adults completed two cognitive tasks measuring processing speed and short-term memory, respectively. Serum concentrations of three inflammatory biomarkers (including interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP)) were measured in each participant. Both cognitive measures showed age-related deficits. In addition, levels of IL-6 and TNF-α were elevated with age. IL-6 partially mediated the difference in processing speed between the young and the older participant age group; there was no mediation effect for TNF-α and CRP. Considering chronological age, IL-6 partially accounted for age-related impairment in processing speed within older but not young participants. No effects were found for short-term memory. Evidence from this research supports the role of inflammatory processes in age-related cognitive decline. Processes involved in this mediation and differences in inflammatory influence on specific cognitive functions are discussed.

Associations between oxytocin receptor gene (OXTR) methylation, plasma oxytocin, and attachment across adulthood

The neuropeptide oxytocin (OT) has been implicated in a wide range of affiliative processes. OT exerts its functions via OT receptors, which are encoded by the oxytocin receptor gene (OXTR). Epigenetic modification of OXTR through the process of DNA methylation has been associated with individual differences in behavioral phenotypes. Specifically, lower levels of OXTR methylation have been linked to better social and affective functioning. However, research on epigenetic mechanisms of OXTR is scarce in non-clinical populations, and even less is known about epigenetic variability across adulthood. The present study assessed methylation levels at OXTR CpG site -934 and plasma OT levels in 22 young (20-31 years, M = 23.6) and 34 older (63-80 years, M = 71.4) participants. Lower levels of OXTR methylation and higher plasma OT levels were associated with less self-reported attachment anxiety in young but not older participants, with largely independent contributions of OXTR methylation and plasma OT levels. In contrast, in the overall sample, lower levels of OXTR methylation were associated with higher self-reported attachment avoidance. Age analysis suggested that these results were largely driven by young adults. Plasma OT levels were unrelated to attachment avoidance. Taken together, these findings support the emerging notion in the literature that epigenetic properties of OXTR, in addition to endogenous OT levels, are related to adult attachment. Further, the age effects observed in the associations between OXTR methylation, plasma OT, and adult attachment emphasize the importance of adopting a developmental perspective when studying properties of the OT system and their relation to affiliative processes. Findings contribute to growing evidence suggesting that epigenetic modification of genes regulating OT pathways and endogenous OT levels are associated with the way people form and maintain intimate social relationships.

Oxytocin shapes the priorities and neural representations of attitudes and values

The phylogenetically ancient neuropeptide oxytocin has been linked to a plethora of social behaviors. Here, we argue that the action of oxytocin is not restricted to the downstream level of emotional responses, but substantially alters higher representations of attitudes and values by exerting a distant modulatory influence on cortical areas and their reciprocal interplay with subcortical regions and hormonal systems.

Oxytocin effects in schizophrenia: Reconciling mixed findings and moving forward

Schizophrenia is a severe mental illness that causes major functional impairment. Current pharmacologic treatments are inadequate, particularly for addressing negative and cognitive symptoms of the disorder. Oxytocin, a neuropeptide known to moderate social behaviors, has been investigated as a potential therapeutic for schizophrenia in recent years. Results have been decidedly mixed, leading to controversy regarding oxytocin's utility. In this review, we outline several considerations for interpreting the extant literature and propose a focused agenda for future work that builds on the most compelling findings regarding oxytocin effects in schizophrenia to date. Specifically, we examine underlying causes of heterogeneity in randomized clinical trials (RCTs) conducted thus far and highlight the complexity of the human oxytocin system. We then review evidence of oxytocin's effects on specific deficits in schizophrenia, arguing for further study using objective, precise outcome measures in order to determine whether oxytocin has the potential to improve functional impairment in schizophrenia.

Oxytocin's effect on resting-state functional connectivity varies by age and sex

The neuropeptide oxytocin plays a role in social cognition and affective processing. The neural processes underlying these effects are not well understood. Modulation of connectivity strength between subcortical and cortical regions has been suggested as one possible mechanism. The current study investigated effects of intranasal oxytocin administration on resting-state functional connectivity between amygdala and medial prefrontal cortex (mPFC), as two regions involved in social-cognitive and affective processing. Going beyond previous work that largely examined young male participants, our study comprised young and older men and women to identify age and sex variations in oxytocin's central processes. This approach was based on known hormonal differences among these groups and emerging evidence of sex differences in oxytocin's effects on amygdala reactivity and age-by-sex-modulated effects of oxytocin in affective processing. In a double-blind design, 79 participants were randomly assigned to self-administer either intranasal oxytocin or placebo before undergoing resting-state functional magnetic resonance imaging. Using a targeted region-to-region approach, resting-state functional connectivity strength between bilateral amygdala and mPFC was examined. Participants in the oxytocin compared to the placebo group and men compared to women had overall greater amygdala-mPFC connectivity strength at rest. These main effects were qualified by a significant three-way interaction: while oxytocin compared to placebo administration increased resting-state amygdala-mPFC connectivity for young women, oxytocin did not significantly influence connectivity in the other age-by-sex subgroups. This study provides novel evidence of age-by-sex differences in how oxytocin modulates resting-state brain connectivity, furthering our understanding of how oxytocin affects brain networks at rest.

Successful aging: Advancing the science of physical independence in older adults

The concept of 'successful aging' has long intrigued the scientific community. Despite this long-standing interest, a consensus definition has proven to be a difficult task, due to the inherent challenge involved in defining such a complex, multi-dimensional phenomenon. The lack of a clear set of defining characteristics for the construct of successful aging has made comparison of findings across studies difficult and has limited advances in aging research. A consensus on markers of successful aging is furthest developed is the domain of physical functioning. For example, walking speed appears to be an excellent surrogate marker of overall health and predicts the maintenance of physical independence, a cornerstone of successful aging. The purpose of the present article is to provide an overview and discussion of specific health conditions, behavioral factors, and biological mechanisms that mark declining mobility and physical function and promising interventions to counter these effects. With life expectancy continuing to increase in the United States and developed countries throughout the world, there is an increasing public health focus on the maintenance of physical independence among all older adults.