Social behaviors in species as diverse as honey bees and humans promote group survival but often come at some cost to the individual. Although reinforcement of adaptive social interactions is ostensibly required for the evolutionary persistence of these behaviors, the neural mechanisms by which social reward is encoded by the brain are largely unknown. Here we demonstrate that in mice oxytocin (OT) acts as a social reinforcement signal within the nucleus accumbens (NAc) core, where it elicits a presynaptically expressed long-term depression of excitatory synaptic transmission in medium spiny neurons. Although the NAc receives OT receptor-containing inputs from several brain regions, genetic deletion of these receptors specifically from dorsal raphe nucleus, which provides serotonergic (5-HT) innervation to the NAc, abolishes the reinforcing properties of social interaction. Furthermore, OT-induced synaptic plasticity requires activation of NAc 5-HT1b receptors, the blockade of which prevents social reward. These results demonstrate that the rewarding properties of social interaction in mice require the coordinated activity of OT and 5-HT in the NAc, a mechanistic insight with implications for understanding the pathogenesis of social dysfunction in neuropsychiatric disorders such as autism.

Dietary supplements, including vitamins, minerals, herbs, amino acids, and enzymes, have become increasingly more common and are used by approximately half of the US population. About three-fourths of supplements are obtained with no prescription from a physician, which raises medical concerns regarding safety as these products do not require US Food and Drug Administration approval. Common reasons for taking dietary supplements include improved mood, improved mental function, depression relief, anxiety reduction, and treatment of simple and migraine headaches. The use of herbs for medicinal purposes has a long-standing history among many cultures. We present the case of a 43-year-old man, who was taking dietary supplements, with a 6-month history of psychotic symptoms that increasingly caused impairment in functioning and eventually led to involuntary hospitalization. The published data with regard to supplements causing psychosis, herb-to-herb interaction, and reliability of herbal supplement manufacturers are discussed.

Cancer therapy-induced complications in the bowel and mesentery are fairly common. It is important for clinicians to be aware of these complications and the agents most frequently implicated. Cancer therapy is rapidly evolving and often encompasses both classic cytotoxic drugs and newer molecular targeted agents. Drugs from both broad classes can have numerous adverse effects on the bowel and mesentery that can be detected on imaging. These adverse effects include ileus, various forms of enterocolitis, gastrointestinal perforation, pneumatosis intestinalis, secretory diarrhea, and sclerosing mesenteritis. These complications are diverse and range from relatively benign to life threatening. The management is also variable, but many of these conditions are easily controlled and reversed with supportive care and cessation of the particular cancer therapy. The objective of this pictorial essay is to demonstrate some of the more common cancer therapy-induced complications of the bowel and mesentery, with a focus on the radiographic findings.

While endometriosis typically affects the ovaries, deep infiltrating endometriosis can affect the gastrointestinal tract, urinary tract, and deep pelvis, awareness of which is important for radiologists. Symptoms are nonspecific and can range from chronic abdominal and deep pelvic pain to nausea, vomiting, diarrhea, constipation, hematuria, and rectal bleeding. Ultrasound and computed tomography may show nonspecific soft-tissue density masses causing bowel obstruction and hydronephrosis. This constellation of presenting symptoms and imaging evidence is easily mistaken for other pathologies including infectious gastroenteritis, diverticulitis, appendicitis, and malignancy, which may lead to unnecessary surgery or mismanagement. With this, deep pelvic endometriosis should be considered in the differential diagnosis in a female patient of reproductive age who presents with such atypical symptoms, and further work up with magnetic resonance imaging is imperative for accurate diagnosis, treatment selection, and preoperative planning.

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