The role of oxytocin in regulation of appetitive behaviour,body weight and glucose homeostasis

Obesity and its associated complications have reached epidemic proportions in the USA and also worldwide, highlighting the need for new and more effective treatments. Although the neuropeptide oxytocin (OXT) is well recognised for its peripheral effects on reproductive behaviour, the release of OXT from somatodendrites and axonal terminals within the central nervous system (CNS) is also implicated in the control of energy balance. In this review, we summarise historical data highlighting the effects of exogenous OXT as a short‐term regulator of food intake in a context‐specific manner and the receptor populations that may mediate these effects. We also describe what is known about the physiological role of endogenous OXT in the control of energy balance and whether serum and brain levels of OXT relate to obesity on a consistent basis across animal models and humans with obesity. We describe recent data on the effectiveness of chronic CNS administration of OXT to decrease food intake and weight gain or to elicit weight loss in diet‐induced obese (DIO) and genetically obese mice and rats. Of clinical importance is the finding that chronic central and peripheral OXT treatments both evoke weight loss in obese animal models with impaired leptin signalling at doses that are not associated with visceral illness, tachyphylaxis or adverse cardiovascular effects. Moreover, these results have been largely recapitulated following chronic s.c. or intranasal treatment in DIO non‐human primates (rhesus monkeys) and obese humans, respectively. We also identify plausible mechanisms that contribute to the effects of OXT on body weight and glucose homeostasis in rodents, non‐human primates and humans. We conclude by describing the ongoing challenges that remain before OXT‐based therapeutics can be used as a long‐term strategy to treat obesity in humans.     

Subtle sex differences in vasopressin mRNA expression in the embryonic mouse brain

Arginine vasopressin (AVP) is a neuropeptide which acts centrally to modulate numerous social behaviors. One receptor subtype through which these effects occur is the AVP 1a receptor (AVPR1A). The modulatory effects of Avp via the AVPR1A varies by species as well as sex, since both AVP and the AVPR1A tend to be expressed more prominently in males. Beyond these neuromodulatory effects there are also indications that the AVP system may play a role in early development to, in part, organize sex‐specific neural circuitry that is important to sexually dimorphic social behaviors in adulthood. However, to date, AVP's role in early development is poorly understood, particularly with respect to its differential effect on males and females. In order to determine the timing and distribution of the AVP system in early brain development, we examined the brains of male and female C57BL/6J mice between embryonic day (E) 12.5 and postnatal day (P) 2 and quantified Avp and Avpr1a mRNA using qPCR and AVPR1A protein using receptor autoradiography. The mRNA for Avp was measurable in males and females starting at E14.5, with males producing more than females, while Avpr1a mRNA was found as early as E12.5, with no difference in expression between sexes. AVPR1A binding was observed in both sexes starting at E16.5, and while there were no observed sex differences, binding density and the number of neuroanatomical areas did increase over time. These data are significant as they provide the first whole‐brain characterization of the vasopressin system in the embryonic mouse. Further, these findings are consistent with data from other species, that have documented a sex difference in the vasopressin system during early brain formation.     

Dysautonomia in early Parkinson disease: a window into the determinants of functional disability and an opportunity for early intervention

Clinical Autonomic Research -     

Relations between Everyday Executive Functioning and Language in Youth with Down Syndrome and Youth with Autism Spectrum Disorder

ABSTRACT

Language and executive functioning are major impairments in many neurodevelopmental disorders, but little is known about the relations between these constructs, particularly using parent-report. Thus, the current research sought to examine relations between executive function and language in two groups – Down syndrome (DS; n=41; M_age = 11.2) and autism spectrum disorder (ASD; n=91; M_age = 7.7). Results were as follows: in DS, executive function predicted pragmatic, but not structural language after covarying for age, sex, and social functioning; in ASD, executive function predicted both. Findings highlight the interrelatedness of language and executive functioning and may have implications for intervention development.     

Commentary: Broadening the research remit of participatory methods in autism science – a commentary on Happé and Frith (2020)

Autism science has transformed beyond recognition in the last two decades. International investment has grown extensively and the number of papers published on autism has increased 10-fold (Pellicano et al., 2014), far surpassing publications on related topics. The sheer amount of scientific research on autism has no doubt been instrumental in many of the discoveries and insights so eloquently described by Happé and Frith (2020). But, as autistic scientist Michelle Dawson reminds us, quality matters too and, for that reason, it is a delight to recognise the contribution that both Happé and Frith have made, dramatically changing our understanding of autism in a host of ways.     

Partner Discussion as a Mediator of the Effects of Mass Media Exposure to FP on Contraceptive Use among Young Nigerians: Evidence from 3 Urban Cities

Evidence suggests that despite high knowledge of family planning (FP), unwanted pregnancies and birth rates remain high among young Nigerians. There is a critical gap in understanding the nexus between exposure to FP information and contraception practices among this population. This study aimed to fill this gap and tested a pathway of the impact of media exposure to FP messages on modern contraceptive use. Data came from a 2018 cross-sectional baseline survey of young people aged 15–24 in three urban centers in Nigeria – Lagos, Kaduna, and Kano. This was part of an impact evaluation of a television-based drama designed to improve contraceptive use among young individuals. The study was limited to 777 young men and women who were sexually active. We found evidence of the mediation effect of media exposure to FP messages on partner discussion about FP, which in turn was associated with an increased likelihood of modern contraceptive use. Contraceptive self-efficacy also had positive associations with contraception. Our study elucidated a potential pathway through which media communication programs can significantly contribute to increased modern contraceptive use and underlined the importance of providing young people in Nigeria with opportunities to learn and practice obtaining and using contraception.