Structural and functional components of the feline enteric nervous system

Neurohistological and immunohistochemical examinations of the feline enteric nervous system (ENS) were performed by using antibodies against neuron-specific enolase (NSE), phosphorylated neurofilaments (PN), non-phosphorylated neurofilaments (NPN) and vasoactive intestinal peptide (VIP), whereas glial cells were investigated by using antibodies against glial fibrillary acidic protein (GFAP). The study included full-thickness biopsies of the stomach, duodenum, jejunum, ileum and colon of 11 healthy cats. In this study, immunohistochemical staining of feline ENS with antibodies to NSE, PN and NPN revealed the presence of different ganglionated and aganglionated plexus. The two ganglionated plexus were arranged in a plexus submucosus internus & externus and a plexus myentericus. Furthermore, plexus mucosus and subserosal plexus represented two aganglionated plexus. GFAP-stained cellular elements were smaller than and in close contact to enteric neurons possibly resembling astrocytes of the central nervous system. VIP is one of the major neurotransmitters of enteric inhibitory neurons, and immunoreactivity was present in all layers of the gut, especially in ganglionated plexus. This is the first report, describing feline ENS by using immunohistochemical methods.