Eliot A Brenowitz

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Seasonal changes in the neural attributes of brain nuclei that control song in songbirds are among the most pronounced examples of naturally occurring plasticity in the adult brain of any vertebrate. The behavioral correlates of this seasonal neural plasticity have not been well characterized, particularly in songbird species that lack adult song learning.(More)
Seasonal plasticity of structure and function is a fundamental feature of nervous systems in a wide variety of animals that occupy seasonal environments. Excellent examples of seasonal brain changes are found in the avian song control system, which has become a leading model of morphological and functional plasticity in the adult CNS. The volumes of entire(More)
Female birds that do not normally sing possess brain nuclei associated with song production in males. To determine whether one song nucleus, the caudal nucleus of the ventral hyperstriatum (HVc), acts in conspecific song perception, courtship responses of female canaries to canary and white-crowned sparrow songs were compared before and after HVc lesions.(More)
There is extensive plasticity of the song behavior of birds and the neuroendocrine circuit that regulates this behavior in adulthood. One of the most pronounced examples of plasticity, found in every species of seasonally breeding bird examined, is the occurrence of large seasonal changes in the size of song control nuclei and in their cellular attributes.(More)
In adult songbirds, seasonal changes in photoperiod and circulating testosterone (T) stimulate structural changes within the neural song control circuitry. The mechanisms that control this natural plasticity are poorly understood. To determine how quickly and in what sequence the song nuclei respond to changing daylength and circulating T, we captured 18(More)
The song control nuclei of songbirds undergo pronounced seasonal changes in size and neuronal attributes. The mechanisms by which seasonal changes in environmental variables such as photoperiod mediate seasonal changes in these brain regions are not known. Manipulations of photoperiod and/or testosterone in captive songbirds induce seasonal changes in the(More)
Differences in neuron density and number are associated with seasonal plasticity and sexual dimorphism in the avian song control system. In previous studies, neuron density and number in this system have been quantified primarily through nonstereological approaches in thick tissue sections by using the nucleolus as the unit of count. The reported(More)
Steroid sex hormones induce dramatic seasonal changes in reproductive related behaviors and their underlying neural substrates in seasonally breeding vertebrates. For example, in adult white-crowned sparrows, increased Spring photoperiod raises circulating testosterone, causing morphological and electrophysiological changes in song-control nuclei, which(More)
In males of several songbird species, the morphology of forebrain nuclei that control song changes seasonally. The only seasonally breeding songbird in which seasonal changes in the structure of song control nuclei have been reported not to occur is the nonmigratory Nuttall's subspecies of white-crowned sparrow. In the present study, we manipulated(More)
Active space, that distance from the source over which signal amplitude remains above the detection threshold of potential receivers, was determined for Red-winged Blackbird (Agelaius phoeniceus) song in an upland pasture near Ithaca, New York. Song amplitude, the rate of signal attenuation, the amplitude of ambient noise, and the sensitivity of redwings to(More)