Postnatal development of nitrergic neurons in the myenteric plexus of rat stomach

Abstract

The effect of age on the proportion of nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd)-positive neurons was investigated in the myenteric plexus of five different gastric areas of 1-day-, 1-week-, 2-week-, 1-month- and 2-month-old rats. Protein gene product 9.5 immunocytochemistry was used as a marker for the total enteric neuron population in order to establish the percentage of gastric nitrergic neurons in relation to age. The percentage of NADPHd-positive neurons in the proximal parts of the rat stomach (34-38%) is significantly higher than in the antral part (29%). This difference persists in all the age groups investigated. No significant relative increase with age of NADPHd-positive neurons could be observed in any of the areas studied. These findings imply that the increased nitrergic response in the rat proximal stomach as seen in pharmacological studies cannot be explained by an increased relative number of nitrergic neurons.

Gastrointestinal Function Regulation by Nitrergic Efferent Nerves

“…The onset and pace of development of nitrergic innervation are similar to adrenergic and cholinergic innervation and occur before peptidergic innervation. In the rat stomach, the percentage of NADPH diaphorase-positive neurons in the proximal part was higher than in the antral part (Timmermans et al, 1999). This difference persisted in groups of 1 day, 1 week, 2 weeks, 1 month, and 2 months of age.…”

Vagal-enteric interface: Vagal activation-induced expression of c-Fos and p-CREB in neurons of the upper gastrointestinal tract and pancreas

“…Although we have not quantitatively assessed the proportion, a good number of the approximately 35% NADPH diaphorase-positive and thus nitrergic neurons (Berthoud, 1995;Timmermans et al, 1999) receive functional vagal input. It has been convincingly shown that nitrergic neurons are responsible for the vagally mediated fundic relaxation response to accommodate ingested food (Desai et al, 1991).…”

Evaluation of the total number of myenteric neurons in the developing chicken gut using cuprolinic blue histochemical staining and neurofilament immunocytochemistry

“…NADH-diaphorase histochemical staining was earlier believed to stain all neurons in the ENS (Gabella 1987), but it was recently demonstrated that the techniques applied are not sufficiently accurate, and 20% of enteric neurons lack NADH-diaphorase (Young et al 1993). PGP 9.5, a neuronal form of ubiquitin, has been utilised as a general neuronal marker (Timmermans et al 1999), although PGP 9.5 immunoreactivity is present in only about 80% of all the myenteric neurons in the rat ENS (Eaker and Sallustio 1994). Neurofilament (NF) immunocytochemistry has been used to evaluate the entire enteric neuron population (Björklund et al 1984) and NF proteins such as NF 200 kDa or NF triplet protein were recently applied as general neuronal markers (Brehmer et al 1999a).…”