Non-sulfated cholecystokinin-8 increases enteric and hindbrain Fos-like immunoreactivity in male Sprague Dawley rats

• Published in: Brain research 2019-04, Vol.1708, p.200-206
• Main Authors: Dafalla, Amged I., Mhalhal, Thaer R., Hiscocks, Kenneth, Heath, John, Sayegh, Ayman I.
• Format: Article
• Language: English
• Subjects: Dorsal vagal complex; Enteric nervous system; Food intake; Fos-like immunoreactivity; Non-sulfated CCK-8
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2018.12.019

•Non-sulfated cholecystokinin-8 (NS CCK-8) reduced food intake.•NS CCK-8 increased Fos-LI immunoreactivity (Fos-LI) in the hindbrain.•NS CCK-8 increased Fos-LI in the myenteric neurons.•NS CCK-8 increased Fos-LI in the submucosal neurons.•These neurons may have a role in reduction of food intake by NS CCK-8. Recently, we reported that non-sulfated cholecystokinin-8 (NS CCK-8) reduces food intake by cholecystokinin-B receptors (CCK-BR). To examine a possible site of action for this peptide, and based on the fact that both NS CCK-8 and CCK-BR are found centrally and peripherally, in the current study we hypothesized that NS CCK-8 increases Fos-like immunoreactivity (Fos-LI, a neuronal activation marker) in the dorsal vagal complex (DVC) of the hindbrain and the myenteric and submucosal plexuses of the small intestine. We found that intraperitoneal NS CCK-8 (0.5 nmol/kg) increases Fos-LI in the DVC, the myenteric and the submucosal plexuses of the duodenum and the myenteric plexus of the jejunum. The findings suggest, but does not prove, a potential role for the DVC and the enteric neurons in the feeding responses evoked by NS CCK-8.