title: Sex differences and endocrine regulation of auditory-evoked, neural responses in African clawed frogs (Xenopus).
abstract: Mating depends on the accurate detection of signals that convey species identity and reproductive state. In African clawed frogs, Xenopus, this information is conveyed by vocal signals that differ in temporal patterns and spectral features between sexes and across species. We characterized spectral sensitivity using auditory-evoked potentials (AEPs), commonly known as the auditory brainstem response, in males and females of four Xenopus species. In female X. amieti, X. petersii, and X. laevis, peripheral auditory sensitivity to their species own dyad-two, species-specific dominant frequencies in the male advertisement call-is enhanced relative to males. Males were most sensitive to lower frequencies including those in the male-directed release calls. Frequency sensitivity was influenced by endocrine state; ovariectomized females had male-like auditory tuning while dihydrotestosterone-treated, ovariectomized females maintained female-like tuning. Thus, adult, female Xenopus demonstrate an endocrine-dependent sensitivity to the spectral features of conspecific male advertisement calls that could facilitate mating. Xenopus AEPs resemble those of other species in stimulus and level dependence, and in sensitivity to anesthetic (MS222). AEPs were correlated with body size and sex within some species. A frequency following response, probably encoded by the amphibian papilla, might facilitate dyad source localization via interaural time differences.
authors.affiliation: Department of Biological Sciences, Columbia University, Fairchild Building, MC 2432, New York, NY, 10027, USA. ich2105@columbia.edu.|Department of Biology, St. Mary's College of Maryland, Schaeffer Hall 258, St. Mary's City, MD, 20686, USA. ich2105@columbia.edu.
authors.forename: Ian C
authors.initials: IC
authors.lastname: Hall
authors.affiliation: Department of Psychology, Columbia University, Schermerhorn Hall, MC 5501, New York, NY, 10027, USA.
authors.forename: Sarah M N
authors.initials: SM
authors.lastname: Woolley
authors.affiliation: Department of Biological Sciences, Columbia University, Fairchild Building, MC 2432, New York, NY, 10027, USA.|Center for New Music and Audio Technologies, University of California, Berkeley, CA, 94720, USA.
authors.forename: Ursula
authors.initials: U
authors.lastname: Kwong-Brown
authors.affiliation: Department of Biological Sciences, Columbia University, Fairchild Building, MC 2432, New York, NY, 10027, USA.
authors.forename: Darcy B
authors.initials: DB
authors.lastname: Kelley
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D062365:Aminobenzoates / Q000494:pharmacology; D000728:Androgens / Q000008:administration & dosage; D000777:Anesthetics / Q000494:pharmacology; D000818:Animals; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology*; D001835:Body Weight; D013196:Dihydrotestosterone / Q000008:administration & dosage; D004703:Endocrine System / Q000187:drug effects / Q000502:physiology*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects / Q000502:physiology*; D005260:Female; D008297:Male; D010052:Ovariectomy; D012727:Sex Characteristics; D013045:Species Specificity; D014828:Vocalization, Animal / Q000502:physiology*; D014981:Xenopus / Q000502:physiology*
chemical_list: D062365:Aminobenzoates; D000728:Androgens; D000777:Anesthetics; C003636:tricaine; D013196:Dihydrotestosterone
keywords: ABR; Androgen; Matched filter; Sex difference; Xenopus