Transplantation of male mouse submaxillary gland increases survival of axotomized basal forebrain neurons.

Transection of the fimbria-fornix results in a loss of magnocellular neurons in the medial septum and vertical limb of the diagonal band (MS/VDB), possibly due to the deprivation of a retrogradely transported trophic substance, such as nerve growth factor (NGF), derived from the hippocampal formation. We have utilized a transplantation model in which grafts of NGF-rich male mouse submaxillary gland were placed in the lateral ventricle adjacent to the MS/VDB of rats with transections of the fimbria-fornix. At 2-4 weeks following transection, animals with grafted submaxillary glands exhibited enhanced survival of MS/VDB neurons, which stained positive for acetylcholinesterase and were immunoreactive for the NGF receptor. These experiments demonstrate that grafts of male mouse submaxillary gland can facilitate the survival of axotomized MS/VDB cholinergic neurons and may therefore prove beneficial in promoting regeneration of damaged neural systems.