Rapid plasticity attenuation soon after birth revealed by habituation in newborn chicks

Abstract

Habituation reflects a form of experience-dependent plasticity whereby the organism progressively learns to ignore the irrelevant information repeatedly encountered. Here, we measured the freezing response to a repeated loud noise in three groups of newborn chicks (Gallus gallus) of different ages (1-2 Day old, 2-3 Day old, and 3-4 Day old) to investigate the ontogeny of habituation in this avian species. Habituation was already present 1 Day after hatching, revealing that the neural mechanisms underlying this form of plasticity are immediately active. Unexpectedly, however, we also found that in the second Day of stimulation the amount of learning was significantly attenuated in chicks of 3-4 days of age as compared to the younger animals, thus showing that 24-48 hr of maturation were sufficient to reduce plasticity. While previous findings in other animal species have proved the existence of a precocious critical period of plasticity in early cortical areas by means of sensory deprivation, our results demonstrate that during the initial development of an intact avian brain also the degree of plasticity underlying a learning process like habituation is maximal soon after birth, and then is subject to a rapid attenuation.

Hier bin Ich: Wo bist Du?

“…This rapid attenuation of plasticity could partly explain the benefits of precocious learning, since it is well known that to acquire full proficiency in some activities, practice should start at an early age during childhood. In avian species, this massive learning capacity is restricted to a narrow time window soon after birth, showing that younger individuals may learn more than their 1-day-older companions (Chiandetti, Dissegna, & Turatto, 2018). Bateson (1964b) found that while chicks approached a novel object on the first day after hatching, on the following 4 days, the majority progressively increased the avoidance of the same object.…”

Analysis of Habituation Learning in Mealworm Pupae (Tenebrio molitor)

“…However, little is known about habituation in Coleoptera, the order of insects that contains the most species compared to any other in the animal kingdom. Some studies have shown that habituation occurs in different species from the first moments of life (e.g., Carew, 1987, 1988;Chiandetti et al, 2018). Furthermore, habituation has been reported even in embryonic stages of domestic chicks (Turatto et al, 2019).…”

Short-term memory in habituation and dishabituation of newborn chicks’ freezing response.

“…To this aim, we explored habituation and dishabituation of the defensive (freezing) response induced by a sudden acoustic stimulation during the early stages of development of a precocial avian species, the chick ( Gallus gallus ). We have already shown that in this species habituation is fully present in the first days after hatching (Chiandetti, Dissegna, & Turatto, 2018; Chiandetti & Turatto, 2017), and by adapting the same paradigm, here we tested whether dishabituation is also present soon after birth (i.e., in 1-day-old chicks) or, alternatively, whether it emerges later during the chick’s ontogenesis (i.e., in 3-day-old chicks).…”