Chronic alcoholism influences the mRNA level of the orexin receptor type 1 (OX1R) in emotiogenic structures of the rat brain

Abstract

Orexin and its receptors were shown to be involved into mechanisms of pathological craving to alcohol. This paper demonstrates that the orexin receptor type 1 (OX1R) mRNA level significantly decreased in the prefrontal cortex of rats chronically (during 6 months) consuming ethanol compared with intact control. The same results were observed on day 1 and day 7 of alcohol withdrawal after chronic alcoholization. On the contrary, in the hippocampus, the OX1R mRNA level increased on day 1 and day 7 of alcohol withdrawal. In the ventral tegmental area, the OX1R mRNA level did not change on the day 1 and day 7 of alcohol withdrawal compared with the groups of chronic alcoholization and intact control. These findings point out involvement of the prefrontal cortex and hippocampus first of all in mechanisms mediating chronic alcohol intoxication. The ventral tegmental area is described as a typical dopaminergic structure providing the executive mechanism of emotion reactions connected with alcohol abuse in particular. It is possibe, that the modulating action of orexins on dopaminergic neurons in this structure does not provide a significant effect on control of emotion reactions in alcoholism.

Involvement of orexinergic system in psychiatric and neurodegenerative disorders: A scoping review

“…[ 1 ] Orexin is responsible for the regulation of weak fullness and arousal, which was discovered in rat brain in 1998 by two researcher groups, one name it hypocretin, since it produced from hypothalamus, and the second group called it orexin from the orexin Greek word which means appetite. [ 2 ]…”

The inhibitory effects of orexin antagonists on the reinforcing properties of amphetamine during brain self-stimulation and the development of a conditioned place preference in rats

“…П.Д. Шабанова [1][2][3][4][5][6][7]. Особенно важна роль орексинов в стремлении к получению наркотика, инициируемая внешними стимулами, то есть мотивационном компоненте зависимости (обсессивно-компульсивном и импульсивном, по терминологии моделируемых состояний) [6].…”

“…Предпосылкой для выполнения настоящей работы послужили данные о возможном вовлечении пептидов орексина в механизмы подкрепления и зависимости от аддиктивных средств. Нейропептиды гипоталамуса орексины, по-видимому, участвуют в механизмах положительного подкрепления, пищевого поведения и механизмах пробуждения (arousal) [7]. Показано, что регуляция системы положительного подкрепления связана с активацией преимущественно OX1R рецепторов орексина [8,19].…”