The Biology of Early Influences

The underlying theme of this book the role of experience in the development of the nervous system. It is now widely acknowledged that there are a variety of organi- environment interactions that guide the development of the nervous system. The popular press has also picked up on this theme and parents are being advised to enrich their child's sensory experience as early as possible. The importance of experience in development is so well accepted that it has begun to dictate public policy. In 1997, the President and First Lady hosted "The White House Conference on Early Childhood Development and Learning: What New Research on the Brain Tells Us About Our Youngest Children. " Along with this conference came a reemphasis on programs directed at enriching the en- ronment of America's youth. In some cases laws have been passed to assure enhanced early experience. In Georgia, the former governor proposed sending newborn children home from the hospital with classical music CDs. This received some praise, but was also ridiculed by others who felt the policy was not justified by the available scientific evidence. Here in Florida, enhanced "brain development activities" are mandated for sta- funded child care facilities. Chapter 402. 25 of the 1998 State of Florida Statues reads (emphasis added): Infants and toddlers in state-funded education and care programs; brain development activities.

Texte du rabat

The role of experience is crucial in the development of the nervous system. The definition of experience includes neural activity, hormonal environment, and social interactions, as well as exposure to sensory stimuli. There are a variety of organism-environment interactions that guide the development of the nervous system. There is evidence that early sensory experiences enhance brain development and make for a more intelligent adult. A common theme throughout the book is the biological mechanism of early experiential influences in neural development. The book covers three stages of development: (1) embryonic or perinatal manipulations; (2) manipulations early after birth or hatching; (3) major periods of transformation in the organism's life. br/ The first stimuli felt by an organism is at the embryonic stage. For example, the expression of prenatal reflexes and movements regulates the life and death of developing neurons and is necessary for the normal development of the nervous system. Another example is the sensory system, the development of which starts before the organism has any sensory input. Furthermore, interactions between a pregnant or nursing female and her environment can influence the environment experienced by her offspring. br/ As regards the organism's development right after birth, evidence suggests that sensory deprivation of a particular system may lead to the death of its neurons. Experiments have been conducted on the olfactory bulb in the rodent and chick auditory systems. br/ The major periods of transformation refer to clear changes in neural structure and function. One of the most extraordinary transformations observed in developing organisms is metamorphosis. During this stage, some neurons may die, others alter their anatomy, take on a new function, and die at a later time. In some organisms, an entirely new sensory epithelium is formed, while in others, learned behavioral changes become biologically possible due to growth of cells that comprise a neural circuit.

Contenu
Lifelong Influences from the Beginning.- Mechanisms of Activity-Dependent Motoneuron Development and Survival in the Chick Embryo.- Cochlear Influences on Development of the Brainstem Auditory System.- Early Influences on Gustatory Development.- Influence of Early Salt Diet on Taste and Blood Pressure in Rats.- Youthful Exposure.- The Role of Early Experience in Olfactory Bulb Cell Survival.- Transneuronal Signals for Afferent Regulation in the Chick Auditory System.- The Developmental Influence of Inhibitory Synaptic Transmission.- Transformations.- Metamorphosis as Midlife Crisis.- Development of the Olfactory System in the African Clawed Frog, Xenopus Laevis.- Afferent Regulation of Developmental Fate in the Songbird Telencephalon.- The Effects of Neuronal Growth and Social Experience on the Development of Behavioral Plasticity.