Fall in density, but not number of myenteric neurons and circular muscle nerve fibres in guinea-pig colon with ageing

Abstract

In guinea-pig ileum, ageing has been associated with a decrease in enteric neurons. This study examined guinea-pig colon and measured changes in gut dimensions, neuron size, density and ganglionic area. Changes in motor nerve fibres in the circular muscle were also measured. Myenteric neurons in whole-mount preparations of mid-colon from 2-week, 6-month, and 2-year-old guinea-pigs were labelled immunohistochemically with the neuronal marker human neuronal protein HuC/HuD, and numbers of neurons mm-2, neuronal size, ganglionic area mm-2, gut length, circumference and muscle thickness were measured. Corrected numbers of neurons mm-2 and ganglionic area mm-2 accounting for growth of the colon w..