Fluorescent Visualisation of Oxytocin in the Hypothalamo-neurohypophysial/-spinal Pathways After Chronic Inflammation in Oxytocin-Monomeric Red Fluorescent Protein 1 Transgenic Rats
JOURNAL OF NEUROENDOCRINOLOGY
Authors: Matsuura, T.; Kawasaki, M.; Hashimoto, H.; Ishikura, T.; Yoshimura, M.; Ohkubo, J. -I.; Maruyama, T.; Motojima, Y.; Sabanai, K.; Mori, T.; Ohnishi, H.; Sakai, A.; Ueta, Y.
Abstract
Oxytocin (OXT) is a well-known neurohypophysial hormone that is synthesised in the paraventricular (PVN) and supraoptic nuclei (SON) of the hypothalamus. The projection of magnocellular neurosecretory cells, which synthesise OXT and arginine vasopressin in the PVN and SON, to the posterior pituitary plays an essential role in mammalian labour and lactation through its peripheral action. However, previous studies have shown that parvocellular OXTergic cells in the PVN, which project to the medulla and spinal cord, are involved in various physiological functions (e.g. sensory modulation and autonomic). In the present study, we examined OXT expression in the PVN, SON and spinal cord after chronic inflammation from adjuvant arthritis (AA). We used transgenic rats that express OXT and the monomeric red fluorescent protein 1 (mRFP1) fusion gene to visualise both the magnocellular and parvocellular OXTergic pathways. OXT-mRFP1 fluorescence intensity was significantly increased in the PVN, SON, dorsal horn of the spinal cord and posterior pituitary in AA rats. The levels of OXT-mRFP1 mRNA were significantly increased in the PVN and SON of AA rats. These results suggested that OXT was up-regulated in both hypothalamic magnocellular neurosecretory cells and parvocellular cells by chronic inflammation, and also that OXT in the PVN-spinal pathway may be involved in sensory modulation. OXT-mRFP1 transgenic rats are a very useful model for visualising the OXTergic pathways from vesicles in a single cell to terminals in invitro preparations.
Blood oxytocin concentration positively predicts contagious yawning behavior in children with autism spectrum disorder
AUTISM RESEARCH
Authors: Mariscal, Michael G.; Oztan, Ozge; Rose, Sophie M.; Libove, Robin A.; Jackson, Lisa P.; Sumiyoshi, Raena D.; Trujillo, Tara H.; Carson, Dean S.; Phillips, Jennifer M.; Garner, Joseph P.; Hardan, Antonio Y.; Parker, Karen J.
Abstract
Research suggests that children with autism spectrum disorder (ASD) may have reduced empathy, as measured by an impaired contagious yawn response, compared to typically developing (TD) children. Other research has failed to replicate this finding, instead attributing this phenomenon to group differences in attention paid to yawn stimuli. A third possibility is that only a subgroup of children with ASD exhibits the impaired contagious yawn response, and that it can be identified biologically. Here we quantified blood concentrations of the "social" neuropeptide oxytocin (OXT) and evaluated yawning behavior and attention rates during a laboratory task in children with ASD (N = 34) and TD children (N = 30) aged 6-12 years. No group difference in contagious yawning behavior was found. However, a blood OXT concentration x group (ASD vs. TD) interaction positively predicted contagious yawning behavior (F-1,F-50 = 7.4987; P = 0.0085). Specifically, blood OXT concentration was positively related to contagious yawning behavior in children with ASD, but not in TD children. This finding was not due to delayed perception of yawn stimuli and was observed whether attention paid to test stimuli and clinical symptom severity were included in the analysis or not. These findings suggest that only a biologically defined subset of children with ASD exhibits reduced empathy, as measured by the impaired contagious yawn response, and that prior conflicting reports of this behavioral phenomenon may be attributable, at least in part, to variable mean OXT concentrations across different ASD study cohorts. Autism Res 2019, 12: 1156-1161. (c) 2019 International Society for Autism Research, Wiley Periodicals, Inc. Lay Summary People with autism may contagiously yawn (i.e., yawn in response to another's yawn) less often than people without autism. We find that people with autism who have lower levels of blood oxytocin (OXT), a hormone involved in social behavior and empathy, show decreased contagious yawning, but those who have higher blood OXT levels do not differ in contagious yawning from controls. This suggests that decreased contagious yawning may only occur in a biologically defined subset of people with autism.