Experimentation animale et éthique

L’expérimentation animale consiste à tester chez l”ºanimal des questions que l”ºon se pose chez l’Homme. En recherches appliquées, ces expérimentations nous fournissent des  données essentielles dans la lutte contre les maladies humaines ainsi qu’en médecine vétérinaire. Em recherches fondamentales, ces expérimentations qui permettent de mieux connaitre l’Homme et l’Animal nous montrent que le fossé que certains voient entre l’espèce humaine et les animaux n’a probablement pas l’importance qu’on lui donne. Ces recherches nous montrent que certains animaux ont quelquefois des capacités cognitives telles qu’ils n’ont rien à envier aux hommes et que ces animaux sont des êtres sensibles capables de souffrir. Toutes ces recherches nous informent sur notre nature, nos relations avec l’animal et notre place dans le monde animal. Ce constat sur la nature et la proximité de l’Homme et de l’Animal a mené à la création des comités d’éthique. Nous avons besoin de ces animaux mais ils méritent notre respect et les expérimentations nécessaires doivent être faites en obéissant à une certaine éthique. Ces comités s’assurent que les expérimentations animales respectent les règles éthiques dont la plus connue est celle des « 3 R » (Remplacement, Réduction et Raffinement

No need to Talk, I Know You: Familiarity Influences Early Multisensory Integration in a Songbird's Brain

It is well known that visual information can affect auditory perception, as in the famous “McGurk effect,” but little is known concerning the processes involved. To address this issue, we used the best-developed animal model to study language-related processes in the brain: songbirds. European starlings were exposed to audiovisual compared to auditory-only playback of conspecific songs, while electrophysiological recordings were made in their primary auditory area (Field L). The results show that the audiovisual condition modulated the auditory responses. Enhancement and suppression were both observed, depending on the stimulus familiarity. Seeing a familiar bird led to suppressed auditory responses while seeing an unfamiliar bird led to response enhancement, suggesting that unisensory perception may be enough if the stimulus is familiar while redundancy may be required for unfamiliar items. This is to our knowledge the first evidence that multisensory integration may occur in a low-level, putatively unisensory area of a non-mammalian vertebrate brain, and also that familiarity of the stimuli may influence modulation of auditory responses by vision

Experience with Adults Shapes Multisensory Representation of Social Familiarity in the Brain of a Songbird

Social animals learn to perceive their social environment, and their social skills and preferences are thought to emerge from greater exposure to and hence familiarity with some social signals rather than others. Familiarity appears to be tightly linked to multisensory integration. The ability to differentiate and categorize familiar and unfamiliar individuals and to build a multisensory representation of known individuals emerges from successive social interactions, in particular with adult, experienced models. In different species, adults have been shown to shape the social behavior of young by promoting selective attention to multisensory cues. The question of what representation of known conspecifics adult-deprived animals may build therefore arises. Here we show that starlings raised with no experience with adults fail to develop a multisensory representation of familiar and unfamiliar starlings. Electrophysiological recordings of neuronal activity throughout the primary auditory area of these birds, while they were exposed to audio-only or audiovisual familiar and unfamiliar cues, showed that visual stimuli did, as in wild-caught starlings, modulate auditory responses but that, unlike what was observed in wild-caught birds, this modulation was not influenced by familiarity. Thus, adult-deprived starlings seem to fail to discriminate between familiar and unfamiliar individuals. This suggests that adults may shape multisensory representation of known individuals in the brain, possibly by focusing the young’s attention on relevant, multisensory cues. Multisensory stimulation by experienced, adult models may thus be ubiquitously important for the development of social skills (and of the neural properties underlying such skills) in a variety of species

Piomiositis a Staphylococcus aureus

Pyomyositis is a pyogenic infection of the skeletal muscles, has predilection for the large muscle masses of the body, with no obvious local or adjacent source of infection. In temperate climates it is strongly related to predisposing factors including diabetes mellitus, HIV infection, malignancies and trauma. The most common etiologic agent is Staphylococcus aureus. A case of non-tropical pyomyositis in an immunocompromised, 50-year-old woman, affecting the iliopsoas, left adductors and left pectineus are presented. Pyomyositis mortality of different series varies from 1% to 23%, depending on the underlying comorbidities of each patient. Diagnosis delay can result in a fatal outcome.La piomiositis es una infección bacteriana del músculo estriado con predilección por los grandes grupos musculares, sin evidencia de causa local o adyacente de infección. En climas templados está fuertemente relacionada a factores predisponentes, entre los que se encuentran diabetes mellitus, infección por VIH, neoplasias malignas y traumatismos. El agente etiológico más frecuente es Staphylococcus aureus. Se presenta el caso de una piomiositis no tropical que afecta los músculos psoas-ilíacos, aductores izquierdos y pectíneo izquierdo, en una mujer de 50 años de edad, inmunocomprometida. La mortalidad de la piomiositis varía en las distintas series entre el 1-23%, dependiendo de las comorbilidades subyacentes de cada paciente. El retraso en el diagnóstico puede ocasionar una evolución fatal

A Potential Neural Substrate for Processing Functional Classes of Complex Acoustic Signals

Categorization is essential to all cognitive processes, but identifying the neural substrates underlying categorization processes is a real challenge. Among animals that have been shown to be able of categorization, songbirds are particularly interesting because they provide researchers with clear examples of categories of acoustic signals allowing different levels of recognition, and they possess a system of specialized brain structures found only in birds that learn to sing: the song system. Moreover, an avian brain nucleus that is analogous to the mammalian secondary auditory cortex (the caudo-medial nidopallium, or NCM) has recently emerged as a plausible site for sensory representation of birdsong, and appears as a well positioned brain region for categorization of songs. Hence, we tested responses in this non-primary, associative area to clear and distinct classes of songs with different functions and social values, and for a possible correspondence between these responses and the functional aspects of songs, in a highly social songbird species: the European starling. Our results clearly show differential neuronal responses to the ethologically defined classes of songs, both in the number of neurons responding, and in the response magnitude of these neurons. Most importantly, these differential responses corresponded to the functional classes of songs, with increasing activation from non-specific to species-specific and from species-specific to individual-specific sounds. These data therefore suggest a potential neural substrate for sorting natural communication signals into categories, and for individual vocal recognition of same-species members. Given the many parallels that exist between birdsong and speech, these results may contribute to a better understanding of the neural bases of speech

Neural Correlates of Experience-Induced Deficits in Learned Vocal Communication

Songbirds are one of the few vertebrate groups (including humans) that evolved the ability to learn vocalizations. During song learning, social interactions with adult models are crucial and young songbirds raised without direct contacts with adults typically produce abnormal songs showing phonological and syntactical deficits. This raises the question of what functional representation of their vocalizations such deprived animals develop. Here we show that young starlings that we raised without any direct contact with adults not only failed to differentiate starlings' typical song classes in their vocalizations but also failed to develop differential neural responses to these songs. These deficits appear to be linked to a failure to acquire songs' functions and may provide a model for abnormal development of communicative skills, including speech

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National audienc

Effets du traumatisme acoustique sur les recepteurs auditifs du poulet : mise en evidence d'une modification de la tonotopie pendant la periode de developpement

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

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National audienc

Expérimentation animale et éthique

National audienc