Neonatal serotonin depletion affects developing and mature mouse cortical neuron

The early expression of neurotransmitters and receptors in the developing b rain has brought attention to their potential contribution in modulating ne uronal developmental processes. Monoamines are among the first neurotransmi tter systems to develop during embryogenesis. Depletion of neocortical sero tonin or catecholamine afferents with selective neurotoxins resulted in a p ermanent alteration of the dendritic arborization of calretinin-containing interneurons, and a transient delay of parvalbumin and calbindin expression in a number of cortical neurones during the second postnatal week. The exp ression pattern of other developmentally regulated proteins, such as two su bunits of the GABA(A) receptor, was not altered. Depletion of serotonin, an d in part catecholamines, appeared to perturb several developmental process es of the cerebral cortex which would interfere with both its maturation an d adult circuitry. NeuroReport 11:833-837 (C) 2000 Lippincott Williams & Wi lkins.