MicroRNA function is required for neurite outgrowth of mature neurons in the mouse postnatal cerebral cortex.

The structure of the postnatal mammalian cerebral cortex is an assembly of numerous mature neurons that exhibit proper neurite outgrowth and axonal and dendritic morphology. While many protein coding genes are shown to be involved in neuronal maturation, the role of microRNAs (miRNAs) in this process is also becoming evident. We here report that blocking miRNA biogenesis in differentiated neurons results in microcephaly like phenotypes in the postnatal mouse brain.

Hyponatremia in the neurosurgical patient: epidemiology, pathophysiology, diagnosis, and management.

Objective: Hyponatremia is an important and common electrolyte disorder in critically ill neurosurgical patients that has been reported in association with a number of different primary diagnoses. The correct diagnosis of the pathophysiological cause is vital because it dramatically alters the treatment approach.

Methods: We review the epidemiology and presentation of patients with hyponatremia, the pathophysiology of the disorder with respect to sodium and fluid balance, and the diagnostic procedures for determining the correct cause.