The molecular focus of my laboratory is identifying the cellular chemicals, especially proteins, which are needed to alter the connections between neurons in the taste aversion circuits. Proteins are encoded by genes. While it is well known that genes determine the structure of body (including the fine structure of the brain) by acting as the "blue-prints" for proteins, the dynamic nature of gene expression is significant. For example, when hair cell needs to grow more hair, it looks to the DNA of the genome to find that blueprint for making hair protein. (If the gene encodes the blueprint for blond hair, the hair cell will grow blond hair). All cells contain the all the genes of the body, but not all cells express all the genes all the time. In some cells, some genes are being referred to continuously: hair cells make hair proteins continuously. Over the course of a lifetime, however, some hair cells will "turn on" hair protein production (e.g. at puberty), while others will "turn off" production (e.g. in male pattern baldness) Likewise, hair cells ignore the genes for neuronal proteins (and vice versa).
In fact, most of the genome is made up of the genes for neuronal proteins. Of the estimated 30,000 genes, 90% are believed to be expressed (used to direct protein synthesis) only in neurons. Many of these genes are expressed only transiently during growth, or when learning changes the circuits of the brain. Thanks to the Human Genome Project, we know have a list of all the genes, but we do not know what structures the brain builds from them. This complexity is a fundamental challenge of neuroscience in the 21st century:
© 2014 T.A. Houpt. Last updated 2014-10-17.