Effect of noradrenergic denervation by neonatal DSP-4 on peptide neurotransmitter systems in the rat brain

The specific effects of a neonatal treatment of rats with the noradrenergic neurotoxin DSP-4 were investigated in the adult rat by measuring monoamine and peptide transmitter levels in eight brain regions. When applied concomitantly with a 5-hydroxytryptamine uptake blocker, neonatal DSP-4 induced a selective depletion of noradrenaline (NA) in cortex, hippocampus and amygdala. An increase of NA was observed in the medulla and substantia nigra/ventral tegmental area and a decrease in dopamine was observed in the thalamus. The vasoactive intestinal polypeptide levels were markedly elevated in the DSP-4 treated rats in almost all CNS regions whereas those of three other neuropeptides remained unchanged. It is concluded that certain adaptational changes can be observed in the peptide systems of the CNS upon disruption of the development of the noradrenergic innervation.