Central nervous system grafts of nerve growth factor-rich tissue as an alternative source of trophic support for axotomized cholinergic neurons

Nerve growth factor (NGF) promotes survival of sympathetic and some neural crest-derived sensory neurons of the peripheral nervous system. This chapter explores the possibility that transplantation of this NGF-rich tissue into the lateral ventricle of the rat may provide a constant source of NGF to axotomized septa1 neurons. The chapter focuses on the grafting of tissue, which synthesizes a trophic factor known to influence the survival of a population of cholinergic neurons in the host brain. The results demonstrate that intraventricular grafts of male mouse submaxillary gland, a rich source of NGF, can increase the survival and regeneration of axotomized medial septum and vertical limb of the diagonal band nuclei (MS/VDB) neurons in the basal forebrain of the rat. The chapter indicates that transplants of male mouse submaxillary gland can (1) survive for extended periods in the host rat CNS, (2) influence the survival and regeneration of axotomized cholinergic cells in the MS/VDB, and (3) possibly influence the expression of behaviors associated with normal cholinergic function. However, further behavioral studies are necessary to determine whether these animals are using extra maze cues or some other non-spatial strategy to locate the platform.