Neural Activity Patterns in Response to Interspecific and Intraspecific Variation in Mating Calls in the Túngara Frog

During mate choice, individuals must classify potential mates according to species identity and relative attractiveness. In many species, females do so by evaluating variation in the signals produced by males. Male túngara frogs (Physalaemus pustulosus) can produce single note calls (whines) and multi-note calls (whine-chucks). While the whine alone is sufficient for species recognition, females greatly prefer the whine-chuck when given a choice.To better understand how the brain responds to variation in male mating signals, we mapped neural activity patterns evoked by interspecific and intraspecific variation in mating calls in túngara frogs by measuring expression of egr-1. We predicted that egr-1 responses to conspecific calls would identify brain regions that are potentially important for species recognition and that at least some of those brain regions would vary in their egr-1 responses to mating calls that vary in attractiveness. We measured egr-1 in the auditory brainstem and its forebrain targets and found that conspecific whine-chucks elicited greater egr-1 expression than heterospecific whines in all but three regions. We found no evidence that preferred whine-chuck calls elicited greater egr-1 expression than conspecific whines in any of eleven brain regions examined, in contrast to predictions that mating preferences in túngara frogs emerge from greater responses in the auditory system.Although selectivity for species-specific signals is apparent throughout the túngara frog brain, further studies are necessary to elucidate how neural activity patterns vary with the attractiveness of conspecific mating calls

Perianal Crohn’s disease: A review

Perianal involvement in Crohn's disease (CD), which encompasses fistulas, ulcers, abscesses, strictures and cancer, can lead to significant impairment in quality of life. The objective of this article is to review the major perianal complications of CD and the current medical and surgical modalities used to treat them. Antibiotics are commonly used despite a lack of controlled trials to validate their use and should be used as a bridge to maintenance therapy. The anti-metabolites azathioprine and 6-MP have shown a positive response in terms of fistula closure, although these data are mostly from trials looking at this as a secondary endpoint. Infliximab is an effective agent for induction and maintenance of treatment of fistulizing CD. Further studies to evaluate the use of subcutaneous anti-tumor necrosis factors are needed to convincingly prove their efficacy for perianal fistulizing disease. In CD, clinicians should avoid surgery as a first-line approach for skin tags, hemorrhoids or fissures in the setting of proctitis. Surgery, particularly lateral internal sphincterotomy, in combination with medical therapy is associated with higher fissure healing rates in the absence of proctitis. Fistulotomy is curative for most simple low perianal fistulae, but complex fistulas often require sphincter-sparing surgical procedures. Less invasive approaches such as a chemical sphincterotomy should be used first, with therapy escalated only if this fails