Biology subjects

Lorenzi, E.

Publications and source records attributed to Lorenzi, E..

5 recordsLinked to original sources

bioRxiv2023

A Kaspar Hauser experiment for innateness of numerical cognition

Whether non-symbolic encoding of quantity is predisposed at birth with dedicated hard-wired neural circuits is debated. Here we presented newly-hatched visually naive chicks with stimuli (flashing dots) of either identical or different numerousness (with a ratio 1:3) with their continuous physical appearance (size, contour length, density, convex hull) randomly changing. Chicks spontaneously tell apart the stimuli on the basis of the number of elements. Upon presentation of either fixed or changing numerousness chicks also showed different expression of early gene c-fos in the visual Wulst, the hippocampal formation, the intermediate medial mesopallium, and the caudal part of the nidopallium caudolaterale. The results support the hypothesis that the ability to discriminate quantities does not require any specific instructive experience. Evidence for innateness of non-symbolic numerical cognition have implications for both neurobiology and philosophy of mathematics.

neuroscience↗

bioRxiv2023

Manganese Enhanced Magnetic Resonance Imaging reveals light-induced brain asymmetry in embryo

The idea that sensory stimulation to the embryo (in utero or in ovo) may be crucial for brain development is widespread. Unfortunately, up to now evidence was only indirect because imaging of embryonic brain activity in vivo was not viable. Here we applied for the first time Manganese Enhanced Magnetic Resonance Imaging (MEMRI) to the eggs of domestic chicks. We revealed light-induced brain asymmetry by comparing embryonic brain activity in vivo of eggs that were stimulated by light or maintained in the darkness. Our protocol paves the way to investigation of the effects of a variety of sensory stimulations on brain activity in embryo. SignificanceSensory stimulation in embryo may be crucial for many aspects of brain and behavioral development (e.g., mother language in humans). However, direct evidence of this is lacking because imaging of embryonic brain activity in vivo is not viable. Here we established a new protocol for measuring embryonic brain activity in vivo in domestic chick eggs. We were able to visualize in vivo the effect of light stimulation on the development of structural brain asymmetries of the embryo. The protocol established paves the way for collecting further evidence on the effects of sensory stimulation on embryonic brain activity.

neuroscience↗

bioRxiv2022

Functional MRI reveals memories of mother in newborn chicks

Filial imprinting has been used as a powerful ethological paradigm to investigate the neurobiology of early learning that affects lifelong behaviours. When a visually naive chick is exposed to one of a wide range of conspicuous objects, it may learn its characteristics and subsequently recognises and selectively approaches this stimulus (usually the mother hen and siblings). While the initial phases of memory acquisition have been unravelled, the long-term storage and retrieval components of imprinting memories are still unknown. Here, we used functional MRI in awake newly hatched chicks to identify the long-term storage of imprinting memories in a wide network comprising the hippocampal formation, the medial striatum, the arcopallium, and the prefrontal-like nidopallium caudolaterale. These results provide the first example of non-invasive imaging of the brain in a newborn vertebrate.

neuroscience↗

bioRxiv2020

Resurgence of a perinatal attraction for animate objects via thyroid hormone T3

For inexperienced brains, some stimuli are more attractive than others. Human neonates and newly-hatched chicks preferentially orient towards face-like stimuli, biological motion, and objects changing speed. In chicks, this enhances exposure to social partners, and subsequent attachment trough filial imprinting. Early preferences are not steady. The preference for stimuli changing speed fades away after three days in chicks. To understand the physiological mechanisms underlying these transient responses, we tested whether the early preferences for objects changing speed can be promoted by thyroid hormone 3,5,3-triiodothyronine (T3). This hormone determines the start of imprintings sensitive period. We found that the preference for objects changing speed can be re-established in female chicks treated with T3. Moreover, day-one chicks treated with an inhibitor of endogenous T3 did not show any preference. These results suggest that the time windows of early predispositions and of high plasticity are controlled by the same molecular mechanisms.

animal behavior and cognition↗

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↗