[Synaptogenesis and synaptic pruning: role in triggering schizophrenia].

An understanding of the pathogenesis of schizophrenia as described by the neurodevelopmental theory requires knowledge of the links between potential etiological factors occurring early in the developmental phase and symptom onset which occurs late in adolescence or early adulthood. Synapse pruning, a phenomenon in which a large proportion of the huge quantity of synapses produced during the developmental stage disappear, occurs during this same period and might play a causal role in triggering schizophrenia. On the basis of other cerebral anomalies reported in the literature as well as clinical and epidemiological data currently available on schizophrenia, the most probable hypotheses integrate synapse pruning as part of a wider disturbance of cerebral development in the prefrontal, temporal and limbic regions. These perturbations may occur early in the pre- or perinatal period, or late during adolescence. It cannot be excluded that abnormal synapse pruning alone may be the underlying cause in a subgroup of schizophrenia patients.