Biology subjects

Rosa-Salva, O.

Publications and source records attributed to Rosa-Salva, O..

5 recordsLinked to original sources

bioRxiv2024

Innate face detectors in the nidopallium of young domestic chicks

Soon after birth, naive animals and newborn babies show spontaneous attraction towards faces and face-like stimuli with three dark features representing eyes and a mouth/beak. While neurons selectively responding to faces have been found in the inferotemporal cortex of adult primates, face-selective domains in the brains of young monkeys seem to develop only later in life after exposure to faces. This has fueled a debate on the role of experience in the development of face-detector mechanisms, since face preferences are well documented in naive animals, such as domestic chicks reared without exposure to faces. Here we demonstrate that neurons in a cortex-homologue area of one-week-old face-naive domestic chicks selectively respond to a face-like configuration. Our single-cell recordings show that these face detectors do not respond to alternative configurations or isolated facial features. Moreover, the population activity of face-selective neurons accurately encoded the face-like stimulus as a unique category. Thus, our findings show that face detectors are present in the brains of very young animals without pre-existing experience.

animal behavior and cognition↗

bioRxiv2021

Visual Field Analysis: a reliable method to score left- and right eye-use using automated tracking

Brain and behavioural asymmetries have been documented in various taxa. Many of these asymmetries involve preferential left- and right-eye use. However, measuring eye use through manual frame-by-frame analyses from video recordings is laborious and may lead to biases. Recent progress in technology allowed the development of accurate tracking techniques for measuring animal behaviour. Amongst these techniques, DeepLabCut, a python-based tracking toolbox using transfer learning with deep neural networks, offers the possibility to track different body parts with unprecedented accuracy. Exploiting the potentialities of DeepLabCut, we developed Visual Field Analysis, an additional open-source application for extracting eye-use data. To our knowledge, this is the first application that can automatically quantify left-right preferences in eye use. Here we test the performance of our application in measuring preferential eye-use in young domestic chicks. The comparison with manual scoring methods revealed a perfect correlation in the measures of eye-use obtained by Visual Field Analysis. With our application, eye-use can be analysed reliably, objectively and at a fine scale in different experimental paradigms.

animal behavior and cognition↗

bioRxiv2021

Spontaneous visual preference for face-like stimuli is impaired in newly-hatched domestic chicks exposed to valproic acid during embryogenesis

One of the most fascinating properties of the human brain is the capacity of newborn babies to recognize and orient to faces and simple schematic face-like patterns since the first hours of life. A striking feature of these social orienting mechanisms is their transversal appearance in remarkably diverse vertebrate species. Similar to newborn babies, also non-human primates and domestic chicks have been shown to express orienting responses to faces and schematic face-like patterns. More importantly, existing studies have hypothesized that early disturbances of these mechanisms represent one of the earliest biomarkers of social deficits in autism spectrum disorders (ASD). Recent data suggest that newborns at high risk for the disorder express altered responses to schematic face-like configurations. Here we modeled ASD in domestic chicks using the anticonvulsant valproic acid (VPA), and tested the animals for their predisposed preference towards schematic face-like configuration stimuli. We found that VPA impairs the chicks preference responses to the social stimuli. Based on the results shown here and in previous studies, we propose the domestic chicks as elective animal models to study early-emerging neurobehavioural markers and to investigate the biological mechanisms underlying face processing deficits in ASD.

neuroscience↗

bioRxiv2018

Embryonic Exposure to Valproic Acid impairs Social Predispositions for Dynamic Cues of Animate Motion in Newly-Hatched Chicks

Predispositions to preferentially orient towards cues associated with social partners, such as face-like stimuli or biological and animate motion, appear to guide social behavior from the onset of life. These predispositions have been documented in several vertebrate species including human neonates, young monkeys and newly-hatched domestic chicks. Human newborns at high familiar risk of Autism Spectrum Disorder (ASD) show a remarkable deficit in their attention toward these predisposed stimuli, either static and dynamic, compared to newborns at low risk. A previous study showed that prenatal exposure to valproic acid (VPA) (that in humans increases the risk of developing ASD) impairs the chicks predisposition to approach naturalistic social stimuli that convey static configurations of features (a stuffed hen), without impairing general cognitive and learning abilities. Here we investigated the effect of VPA exposure on another class of social predispositions, i.e. the spontaneous preference to approach self-propelled objects, namely objects that display autonomous changes in speed. We observed that the preference for stimuli displaying autonomous changes in speed was impaired in VPA-compared to vehicle-injected chicks. Our results indicate an effect of VPA on the development of predisposed orienting mechanisms towards dynamic stimuli, that could be used to investigate the molecular and neurobiological mechanisms underlying ASD early symptoms.

neuroscience↗

bioRxiv2017

Embryonic Exposure to Valproic Acid Disrupts Social Predispositions in Newly-Hatched Chicks

Biological predispositions to attend to visual cues, such as those associated with face-like stimuli or with biological motion, guide social behavior from the first moments of life and have been documented in human neonates, infant monkeys and newly-hatched domestic chicks. In human neonates at high familial risk of Autism Spectrum Disorder (ASD), a lack of such predispositions has been recently reported. Prompted by these observations, we modeled ASD behavioral deficit in newborn chicks, using embryonic exposure to valproic acid (VPA), the histone deacetylases (HDACs) inhibitor that in humans is associated with an increased risk for developing ASD. We assessed spontaneous predispositions in newly-hatched, visually-naive chicks, by comparing responses to a stuffed hen vs. a scrambled version of it. We found that social predispositions were abolished in VPAtreated chicks. In contrast, experience-dependent learning mechanisms associated with filial imprinting were not affected. Our results indicate a specific effect of VPA on the development of biologically-predisposed social orienting mechanisms, opening new perspectives to investigate the molecular and neurobiological mechanisms involved in early ASD symptoms.

neuroscience↗