Expression and function of brain specific small RNAs.

Small non-messenger RNAs (snmRNAs) are a heterogeneous group of non-coding RNAs with a variety of regulatory functions including regulation of protein expression and guidance in RNA modifications. They are actively being investigated in Archaebacteria, yeast, invertebrates and mammals. Brain-specific snmRNAs have been identified in mammals and they seem to contribute to neuronal differentiation during development and to brain functions subserving learning and memory. Here we review the current knowledge of the properties, expression and functions of three groups of brain-specific snmRNAs: small nucleolar RNAs, BC1/BC200 RNAs and microRNAs.