Neuron Number in the Intestinal Myenteric Plexus of the Domestic Fowl (Gallus gallus)

The number of neurons in the myenteric plexus of the duodenum, jejunum, ileum, rectum and cecum of chick and adult domestic fowl (Gallus gallus) was counted. Gradients of neuron density were observed in the small and large intestines, the difference between the neuron densities in adjacent regions generally being significant. The mean neuron density in each region in the chick was two to three times higher than in the adult. The concentration of neurons was significantly greater in the mesenteric zone of the plexus than in the antimesenteric zone. The total number of neurons in the adult was significantly higher than in the chick. The differences between the neuron counts in the chicks and adults are discussed.