Morphofunctional interaction of CART peptide and dopaminergic brain neurons

Abstract

In Wistar rats, after 6 h of sleep deprivation and subsequent 2 h postdeprivation sleep, we found significant changes in optical density of CART-peptide in neurons of hypothalamic nucleus accumbens and nucleus arcuatus as well as in processes coming into substantia nigra from nucleus accumbens. The obtained data revealed unidirectional changes of optical density of tyrosine hydroxylase: a decrease after sleep deprivation (p < 0.05) and, on the contrary, an increase on the background of postdeprivation sleep (p < 0.05). Confocal laser microscopy showed morphological connections of CART and dopaminergic neurons and possible colocalization of these both substances in the same neuron at the postdeprivation sleep. In experiments in vitro, after 1 h of incubation of survived brain slices from the substantia nigra area in the medium with CART-peptide there was revealed a rise of optical density of tyrosine hydroxylase in the substantia nigra compact part by 55 % (p < 0.05). The obtained data indicate an activating effect of CART-peptide on brain dopaminergic neurons and its as a modulator of their functional activity.