APOPTOSIS IN DEVELOPMENT AND DISEASE OF THE NERVOUS-SYSTEM .1. NATURALLY-OCCURRING CELL-DEATH IN THE DEVELOPING NERVOUS-SYSTEM

In recent years, apoptosis, the process by which cells orchestrate the ir own demise, has been the subject of increasingly intense investigat ion, both from the stand-point of basic mechanisms of signal transduct ion and with regard to its role in normal and pathological processes i n the nervous system, For the neurologist, an understanding of the mec hanisms by which apoptosis determines at a cellular level the normal f orm of the nervous system, an appreciation of how both unchecked apopt osis and failure of enactment of the apoptotic pathway contribute to n ervous system pathology and a sense of how both induction and inhibiti on of apoptosis can be exploited therapeutically are critical to apply ing the basic knowledge in this field to human disease, Early studies made it clear that substances produced by the target tissue influenced the survival of developing neurons, More recent investigations have d emonstrated that they do so by influencing the production of a series of endogenous mediators and modulators of neuronal survival. Furthermo re, it is evident that apoptosis is important for the development of b oth neuronal and non-neuronal cells in the peripheral and central nerv ous systems.