Scientific Report 2004

Section Cover for the Department of Neurobiology:
Schematic representation of the transcription, transport, and translation of mRNAs that localize to the dendrites of neurons. Neurons, the impulse-conducting cells of the brain, contain a cell body or soma, an axonal fiber that carries the neuron’s output, and one or more dendritic processes, which receive incoming signals at points of neuron-neuron contact called synapses. In neurons, as in all cells, a variety of genes are transcribed into mRNA and translated into protein. Most of this translation occurs within the soma; however, a subset of neuronal mRNAs contains specific sequences that enable the mRNAs to be transported out of the cell body and into dendrites. Translation of dendritically localized mRNAs has been implicated in learning and memory; this local translation is thought to enable synapses to be modified according to their activity, thereby affecting how efficiently they transmit nerve impulses. Members of our department have shown that at least 5 dendritically localized mRNAs have special sequences called internal ribosome entry sites that allow these mRNAs to be translated independently of the cap, suggesting that cap-independent mechanisms may enable the efficient translation of these mRNAs in dendrites. The artwork was done by Vincent P. Mauro, Ph.D.