Evidence for a satellite secretory pathway in neuronal dendritic spines

Long-term information storage within the brain requires the synthesis of ne w proteins and their use in synapse-specific modifications [1]. Recently, w e demonstrated that translation sites for the local synthesis of integral m embrane and secretory proteins occur within distal dendritic spines [2], It remains unresolved, however, whether a complete secretory pathway, includi ng Golgi and trans Golgi network-like membranes, exists near synapses for t he local transport and processing of newly synthesized proteins. Here, we r eport evidence of a satellite secretory pathway in distal dendritic spines and distal dendrites of the mammalian brain. Membranes analogous to early ( RER and ERGIC), middle (Golgi cisternae), and late (TGN) secretory pathway compartments are present within dendritic spines and in distal dendrites, L ocal synthesis, processing, and transport of newly translated integral memb rane and secretory proteins may thus provide the molecular basis for synaps e-specific modifications during long-term information storage in the brain. (C) 2001 Elsevier Science Ltd. All rights reserved.