Adolescent social isolation disrupts developmental tuning of neuropeptide circuits in the hypothalamus to amygdala regulating social and defensive behavior.

Engaging in positive social (i.e., prosocial) interactions during adolescence acts to modulate neural circuits that determine adult adaptive behavior. While accumulating evidence indicates that a strong craving for prosocial behavior contributes to sustaining neural development, the consequences of social deprivation during adolescence on social neural circuits, including those involving oxytocin (OXT) and vasopressin (AVP), are poorly characterized. We evaluated adaptive behaviors in socially isolated mice, including anxiety-like, social, and defensive behaviors, along with OXT and AVP neural profiles in relevant brain regions. Social isolation from postnatal day (P-)22 to P-48 induced enhanced defensive and exploratory behaviors, in nonsocial and social contexts. Unlike OXT neurons, AVP+ cell density in the paraventricular nucleus of the hypothalamus increases with age in males. Social isolation also modulated gene expression in the medial amygdala (MeA), including the upregulation of OXT receptors in males and the downregulation of AVP1a receptors in both sexes. Socially isolated mice showed an enhanced defensive, anogenital approach toward a novel adult female during direct social interactions. Subsequent c-Fos mapping revealed diminished neural activity in restricted brain areas, including the MeA, lateral septum, and posterior intralaminar nucleus of the thalamus, in socially isolated mice. These data indicate that neural signals arising from daily social interactions invoke region-specific modification of neuropeptide expression that coordinates with altered defensiveness and neural responsivities, including OXT- and AVP-projecting regions. The present findings indicate an involvement of OXT and AVP circuits in adolescent neural and behavioral plasticity that is tuned by daily social interaction.

Complementary effect of oral administration of Lactobacillus paracasei K71 on canine atopic dermatitis.

BACKGROUND: Atopic dermatitis is a common skin disease encountered in dogs. Glucocorticoids are commonly recommended for symptomatic therapy and well-tolerated adjunctive therapies may help to reduce the necessary dose and associated risks of chronic glucocorticoid use. HYPOTHESIS/OBJECTIVES: The purpose of this study was to evaluate the complementary efficacy of oral administration of Lactobacillus paracasei K71 in canine atopic dermatitis (cAD). ANIMALS: Forty one dogs with mild to moderate cAD were recruited by19 animal hospitals. METHODS: Dogs were assigned to receive either the investigational agent (K71 group; n = 20) or cetirizine hydrochloride (control group; n = 21). Previously prescribed medications were allowed to be continued during the 12 week trial. Dogs were assessed by the investigators using the cAD Extent and Severity Index (CADESI) and a medication scoring system. Pet owners assessed their dogs using a visual analog scale (VAS) and pruritus scores. RESULTS: The CADESI scores, VAS and pruritus scores in both groups at 12 weeks were improved compared with their baselines. The CADESI and pruritus scores in the K71 group were slightly lower than those in the control group and the reduction of medication scores in the K71 group was significantly lower compared with the control group (P < 0.05; Student's t-test). CONCLUSIONS AND CLINICAL IMPORTANCE: Oral administration of K71 can be useful in dogs with cAD as a complementary therapy, by providing a steroid-sparing effect.