These authors contributed equally to the study.The ability to recognize close relatives in order to cooperate or to avoid inbreeding is widespread across all taxa. One accepted mechanism for kin recognition in birds is associative learning of visual or acoustic cues. However, how could individuals ever learn to recognize unfamiliar kin? Here, we provide the first evidence for a novel mechanism of kin recognition in birds. Zebra finch (Taeniopygia guttata) fledglings are able to distinguish between kin and non-kin based on olfactory cues alone. Since olfactory cues are likely to be genetically based, this finding establishes a neglected mechanism of kin recognition in birds, particularly in songbirds, with potentially far-reaching consequences for both kin selection and inbreeding avoidance.
Our objective is to determine whether the degree of endolymphatic hydrops as it is detected in vivo in patients with definite Meniere's disease correlates with audiovestibular function. In this prospective study, 37 patients with definite Meniere's disease according to AAO-HNS criteria were included. Intratympanic contrast enhanced temporal bone MRI was performed using a 3D FLAIR protocol. The degree of endolymphatic hydrops in the cochlea and the vestibulum was graded on a Likert scale (0-3). The degree of hydrops was then analyzed with respect to its correlation with audiometric hearing levels, electrocochleographic SP/AP ratios, interaural amplitude ratios of vestibular evoked myogenic potentials and degree of horizontal semicircular canal paresis on caloric irrigation. There was a significant correlation between the degree of hydrops on the one hand and the averaged hearing level at 0.25-1 and 0.5-3 kHz and the vestibular evoked myogenic potential interaural amplitude ratio on the other hand. A trend toward a correlation was noticed between the hydrops and the caloric response, no correlation was noticed between the hydrops and the SP/AP ratio. The degree of endolymphatic hydrops correlates with a progressive loss of auditory and sacculus function in patients with Meniere`s disease.
Conditions experienced during early life can have profound effects on individual development and condition in adulthood. Differences in nutritional provisioning in birds during the first month of life can lead to differences in growth, reproductive success and survival. Yet, under natural conditions shorter periods of nutritional stress will be more prevalent. Individuals may respond differently, depending on the period of development during which nutritional stress was experienced. Such differences may surface specifically when poor environmental conditions challenge individuals again as adults. Here, we investigated long term consequences of differences in nutritional conditions experienced during different periods of early development by female zebra finches (Taeniopygia guttata) on measures of management and acquisition of body reserves. As nestlings or fledglings, subjects were raised under different nutritional conditions, a low or high quality diet. After subjects reached sexual maturity, we measured their sensitivity to periods of food restriction, their exploration and foraging behaviour as well as adult resting metabolic rate (RMR). During a short period of food restriction, subjects from the poor nutritional conditions had a higher body mass loss than those raised under qualitatively superior nutritional conditions. Moreover, subjects that were raised under poor nutritional conditions were faster to engage in exploratory and foraging behaviour. But RMR did not differ among treatments. These results reveal that early nutritional conditions affect adult exploratory behaviour, a representative personality trait, foraging and adult's physiological condition. As early nutritional conditions are reflected in adult phenotypic plasticity specifically when stressful situations reappear, the results suggest that costs for poor developmental conditions are paid when environmental conditions deteriorate.
In patients with clinically and electrocochleographically confirmed definite Ménière's disease, the degree of MR morphological hydrops severity correlates significantly with impairment of hearing function and sacculus function.
Vertigo patients exhibiting features of vestibular migraine (VM) and Menière's disease (MD) present a difficult diagnostic challenge to the clinician, and the two entities are likely to overlap. The aim of the present study was to investigate the occurrence of endolymphatic hydrops in patients with VM and auditory symptoms. This was an observatory diagnostic study. At an academic interdisciplinary dizziness centre, nineteen consecutive patients with definite or probable VM and auditory symptoms were examined by locally enhanced inner ear MR imaging. MR images were evaluated for the presence of endolymphatic hydrops. Of the 19 included patients, four patients (21 %) demonstrated evidence of cochlear and vestibular endolymphatic hydrops on locally enhanced inner ear MR imaging (three with "definite VM", one with "probable VM"). Locally enhanced inner ear MR imaging may be useful in the diagnostic evaluation of patients with VM and auditory symptoms, as some of these patients have signs of endolymphatic hydrops. Whether these patients suffer from MD only and are misdiagnosed as VM or suffer from both, VM and MD or whether endolymphatic hydrops is a consequence of inner ear damage due to VM are clinically relevant questions that can be evaluated by application of this technique.
Cochlear implantation is a relevant risk factor for damage of peripheral vestibular receptor function. Therefore, preservation not only of residual hearing function but also of vestibular function should be aimed for, by using minimally invasive surgical techniques.
International audienceOur understanding of fundamental organismal biology has been disproportionately influenced by studies of a relatively small number of ‘model’ species extensively studied in captivity. Laboratory populations of model species are commonly subject to a number of forms of past and current selection that may affect experimental outcomes. Here, we examine these processes and their outcomes in one of the most widely used vertebrate species in the laboratory – the zebra finch (Taeniopygia guttata). This important model species is used for research across a broad range of fields, partly due to the ease with which it can be bred in captivity. However despite this perceived amenability, we demonstrate extensive variation in the success with which different laboratories and studies bred their subjects, and overall only 64% of all females that were given the opportunity, bred successfully in the laboratory. We identify and review several environmental, husbandry, life-history and behavioural factors that potentially contribute to this variation. The variation in reproductive success across individuals could lead to biases in experimental outcomes and drive some of the heterogeneity in research outcomes across studies. The zebra finch remains an excellent captive animal system and our aim is to sharpen the insight that future studies of this species can provide, both to our understanding of this species and also with respect to the reproduction of captive animals more widely. We hope to improve systematic reporting methods and that further investigation of the issues we raise will lead both to advances in our fundamental understanding of avian reproduction as well as to improvements in future welfare and experimental efficiency
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