Ok, there might once be a pill for inducing critical learning periods, still, those early years are so important as also new research proves, new research by rats that is. By carefully watching nearly a hundred hours of video showing mother rats protecting, warming, and feeding their young pups, and then matching up what they saw to real-time electrical readings from the pups’ brains, researchers have found that the mother’s presence and social interactions – her nurturing role – directly molds the early neural activity and growth of her offsprings’ brain.
From the press release:
Although scientists have known for decades that maternal-infant bonding affects neural development, the NYU Langone team’s latest findings are believed to be the first to show — as it is happening — how such natural, early maternal attachment behaviors, including nesting, nursing, and grooming of pups, impact key stages in postnatal brain development.
Researchers say the so-called slow-wave, neural signaling patterns seen during the initial phases of mammalian brain development — between age 12 and 20 days in rats — closely resembled the electrical patterns seen in humans for meditation and conscious and unconscious sleep-wake cycles, and during highly focused attention. These early stages are when permanent neural communication pathways are known to form in the infant brain, and when increasing numbers of nerve axons become sheathed, or myelinated, to speed neural signaling.
According to senior study investigator and neurobiologist Regina Sullivan, PhD, whose previous research in animals showed how maternal interactions influenced gene activity in the infant brain, the latest study offers an even more profound perspective on maternal caregiving.
“Our research shows how in mammals the mother’s sensory stimulation helps sculpt and mold the infant’s growing brain and helps define the role played by ‘nurturing’ in healthy brain development, and offers overall greater insight into what constitutes good mothering,” says Sullivan, a professor at the NYU School of Medicine and its affiliated Nathan S. Kline Institute for Psychiatric Research. “The study also helps explain how differences in the way mothers nurture their young could account, in part, for the wide variation in infant behavior among animals, including people, with similar backgrounds, or in uniform, tightly knit cultures.”
“There are so many factors that go into rearing children,” says lead study investigator Emma Sarro, PhD, a postdoctoral research fellow at NYU Langone. “Our findings will help scientists and clinicians better understand the whole-brain implications of quality interactions and bonding between mothers and infants so closely after birth, and how these biological attachment behaviors frame the brain’s hard wiring.”
Abstract of the study:
Patterns of neural activity are critical for sculpting the immature brain, and disrupting this activity is believed to underlie neurodevelopmental disorders [ 1–3 ]. Neural circuits undergo extensive activity-dependent postnatal structural and functional changes [ 4–6 ]. The different forms of neural plasticity [ 7–9 ] underlying these changes have been linked to specific patterns of spatiotemporal activity. Since maternal behavior is the mammalian infant’s major source of sensory-driven environmental stimulation and the quality of this care can dramatically affect neurobehavioral development [ 10 ], we explored, for the first time, whether infant cortical activity is influenced directly by interactions with the mother within the natural nest environment. We recorded spontaneous neocortical local field potentials in freely behaving infant rats during natural interactions with their mother on postnatal days ∼12–19. We showed that maternal absence from the nest increased cortical desynchrony. Further isolating the pup by removing littermates induced further desynchronization. The mother’s return to the nest reduced this desynchrony, and nipple attachment induced a further reduction but increased slow-wave activity. However, maternal simulation of pups (e.g., grooming and milk ejection) consistently produced rapid, transient cortical desynchrony. The magnitude of these maternal effects decreased with age. Finally, systemic blockade of noradrenergic beta receptors led to reduced maternal regulation of infant cortical activity. Our results demonstrate that during early development, mother-infant interactions can immediately affect infant brain activity, in part via a noradrenergic mechanism, suggesting a powerful influence of the maternal behavior and presence on circuit development.