Intraventricular nerve growth factor administration prevents lesion-induced loss of septal cholinergic neurons in aging rats.

In young adult rats transection of the fimbria results in loss of cholinergic cell bodies in the septum and this lesion-induced loss is prevented by intraventricular administration of NGF. The present study examined whether NGF administration is equally effective in aging animals. Eighteen-month-old rats received fimbrial transections and were given intraventricular injections of NGF during four weeks. Septal cholinergic neurons were then visualized using NGF receptor immunohistochemistry, which represents a reliable marker for cholinergic neurons in the septal area. The fimbrial transections reduced the number of septal NGF receptor-positive cells to a similar extent as in young animals. NGF treatment of aging rats protected these cells as effectively as in young adult rats.