Monoamine concentrations in brain regions of the developing rabbit

Growth patterns in selected areas of rabbit brain were studied neurochemically by assaying for norepinephrine, dopamine and serotonin from the neonatal to adult stages of development. These measurements showed that the various monoamines reached adult concentrations at different rates within a brain region; each region had a unique pattern of amine development. Changes in content were most marked in the first 2 weeks of life. Concentration increases were pronounced for norepinephrine and serotonin in the hypothalamus and for dopamine in the caudate nucleus. By contrast, norepinephrine concentrations in the pons-medulla and colliculi were relatively stable. The marked changes and differences in amine concentrations of maturing rabbit brain provide basic data on monoaminergic innervation of discrete regions and indicate the rabbit merits consideration in neurochemical and physiologic studies on the development of neurotransmission.