Our thoughts and behavior reflect the concerted functioning of millions of brain neurons that are intricately and precisely connected. These connections form a biological circuit underlying a remarkable computing machine, one whose connections are shaped by adaptation and experience.
Evidence indicates that both genes and experience are involved.
During prenatal and early postnatal development, genetically specified molecular cues direct the formation of connections between the major centers of the mammalian brain, but these initial connections are often diffuse, lacking the network precision necessary to process complex sensory information. Through a gradual process of remodeling and refinement, the precision of mature connections is eventually attained. This process takes place largely during childhood, when neural connections are highly plastic. To provide answers to these questions, my laboratory examines the development of visual connections in the mouse forebrain. During the first month of life, dramatic changes occur in the pattern of synaptic connections within the thalamus and visual cortex.