The neuropeptide oxytocin (OXT) has generated considerable interest as potential treatment for psychiatric disorders, including anxiety and autism spectrum disorders. However, the behavioral and molecular consequences associated with chronic OXT treatment and chronic receptor (OXTR) activation have scarcely been studied, despite the potential therapeutic long-term use of intranasal OXT. Here, we reveal that chronic OXT treatment over two weeks increased anxiety-like behavior in rats, with higher sensitivity in females, contrasting the well-known anxiolytic effect of acute OXT. The increase in anxiety was transient and waned 5 days after the infusion has ended. The behavioral effects of chronic OXT were paralleled by activation of an intracellular signaling pathway, which ultimately led to alternative splicing of hypothalamic corticotropin-releasing factor receptor 2α (Crfr2α), an important modulator of anxiety. In detail, chronic OXT shifted the splicing ratio from the anxiolytic membrane-bound (mCRFR2α) form of CRFR2α towards the soluble CRFR2α (sCRFR2α) form. Experimental induction of alternative splicing mimicked the anxiogenic effects of chronic OXT, while sCRFR2α-knock down reduced anxiety-related behavior of male rats. Furthermore, chronic OXT treatment triggered the release of sCRFR2α into the cerebrospinal fluid with sCRFR2α levels positively correlating with anxiety-like behavior. In summary, we revealed that the shifted splicing ratio towards expression of the anxiogenic sCRFR2α underlies the adverse effects of chronic OXT treatment on anxiety.

Social interactions are critical for mammalian survival and evolution. Dysregulation of social behavior often leads to psychopathologies such as social anxiety disorder, denoted by intense fear and avoidance of social situations. Using the social fear conditioning (SFC) paradigm, we analyzed expression levels of miR-132-3p and miR-124-3p within the septum, a brain region essential for social preference and avoidance behavior, after acquisition and extinction of social fear. Here, we found that SFC dynamically altered both microRNAs. Functional in vivo approaches using pharmacological strategies, inhibition of miR-132-3p, viral overexpression of miR-132-3p, and shRNA-mediated knockdown of miR-132-3p specifically within oxytocin receptor-positive neurons confirmed septal miR-132-3p to be critically involved not only in social fear extinction, but also in oxytocin-induced reversal of social fear. Moreover, Argonaute-RNA-co-immunoprecipitation-microarray analysis and further in vitro and in vivo quantification of target mRNA and protein, revealed growth differentiation factor-5 (Gdf-5) as a target of miR-132-3p. Septal application of GDF-5 impaired social fear extinction suggesting its functional involvement in the reversal of social fear. In summary, we show that septal miR-132-3p and its downstream target Gdf-5 regulate social fear expression and potentially mediate oxytocin-induced reversal of social fear.

Background/Objectives: Chronic macular edema (CME) is a common complication of diabetic retinopathy or non-infectious uveitis affecting the posterior segment (NIU-PS). Alongside anti-VEGF therapy, glucocorticoids are frequently used to manage CME. Given the heterogeneous nature of patients’ medical history, their social conditions, and disease manifestations, individualized treatment is essential for optimal outcomes. This study assesses the effectiveness of intravitreal fluocinolone acetonide (FA) (Iluvien^®) in treating persistent and recurrent macular edema in clinical practice at the University Hospital of Erlangen–Nuremberg, Germany. Methods: A total of 46 eyes with diabetic macular edema (DME) (21 eyes) and NIU-PS (25 eyes) were retrospectively analyzed over a follow-up period of up to 36 months. Since persistent retinal thickness fluctuations are linked to long-term retinal damage and functional decline, this study analyzed central retinal thickness (CRT)—including its fluctuations measured as CRT amplitude—alongside BCVA as the primary outcomes. Results: After an initial decrease in CRT in the first year after FA treatment, the maximum CRT amplitude significantly decreased in the following years. For patients with DME, CRT amplitude reduced from 271.4 µm to 91.57 µm in the first year (p = 0.0056) and 106.0 µm in the second year (p = 0.0109). For patients with NIU-PS, CRT amplitude decreased from 185.2 µm to 87.7 µm in the first year (p = 0.0131) and 97.3 µm in the second year (p = 0.0375). Mean BCVA remained stable in both cohorts. Conclusions: Intravitreal FA proved to be effective in reducing and stabilizing CRT in patients with chronic DME and NIU-PS without losing visual acuity, reducing treatment burden.