Читать книгу Abnormal Psychology - William J. Ray - Страница 99

In terms of behavior and experience, the production of proteins can be transitory. For example, touching a cat’s whiskers causes changes in gene expression in the cells of the sensory cortex of the brain (Mack & Mack, 1992). This is just a momentary change. Changes can also be long term. Turning on one set of genes may have lasting influence on the ability of other genes to produce specific proteins. For example, when a songbird first hears the specific song of its species, a particular set of genes comes into play, which, once set, determine the song produced by that bird for its entire life. This process has been mapped by a number of researchers (see, for example, Mello, Vicario, & Clayton, 1992; Ribeiro & Mello, 2000). Likewise, raising mice in an enriched environment—that is, one with lots of toys and stimulation—will cause increased gene expression in genes that are associated with learning and memory (Rampon et al., 2000).

When a songbird first hears the specific song of its species, a particular set of genes comes into play, which, once set, determine the song produced by that bird for its entire life.

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How do we know which genes are involved? In the Rampon et al. (2000) study, the genes of mice in enriched environments were compared with those of control mice who did not have this experience. Another way to know which genes are involved in a process is to actually change the genes in a particular organism. So-called “knockout” mice are genetically engineered to have particular genes turned off by breeding them in specific ways. Research shows that simple genetic changes made experimentally in animals can result in protein changes that influence social behavior. Some examples of such behaviors are increased fear and anxiety, increased grooming, hyperactivity, and even increased alcohol consumption when stressed.