Hypothalamic tissue stimulates hippocampal pyramidal neuron survival during development: evidence from intraocular double transplants

Kidney Cografts Enhance Fiber Outgrowth from Ventral Mesencephalic Grafts to the 6-Ohda–Lesioned Striatum, and Improve Behavioral Recovery

Recent studies have demonstrated the presence of many different neurotrophic factors in the developing and adult kidney. Due to its production of this mixture of neurotrophic factors, we wanted to investigate whether fetal kidney tissue could be beneficial for neuritic fiber growth and/or cell survival in intracranial transplants of fetal ventral mesencephalic tissue (VM). A retrograde lesion of nigral dopaminergic neurons was performed in adult Fischer 344 male rats by injecting 6-hydroxydopamine into the medial forebain. The animals were monitored for spontaneous locomotor activity in addition to apomorphine-induced rotations once a week. Four weeks following the lesion, animals were anesthetized and embryonic day 14 VM tissue from rat fetuses was implanted stereotaxically into the dorsal striatum. One group of animals received a cograft of kidney tissue from the same embryos in the same needle track. The animals were then monitored behaviorally for an additional 4 months. There was a significant improvement in both spontaneous locomotor activity (distance traveled) and apomorphine-induced rotations with both single VM grafts and VM–kidney cografts, with the VM–kidney double grafts enhancing the motor behaviors to a significantly greater degree. Tyrosine hydroxylase (TH) immunohistochemistry and image analysis revealed a significantly denser innervation of the host striatum from the VM–kidney cografts than from the single VM grafts. TH-positive neurons were also significantly larger in the cografts compared to the single VM grafts. In addition to the dense TH-immunoreactive innervation, the kidney portion of cografts contained a rich cholinergic innervation, as evidenced from antibodies against choline acetyltransferase (ChAT). The striatal cholinergic cell bodies surrounding the VM–kidney cografts were enlarged and had a slightly higher staining density for ChAT. Taken together, these data support the hypothesis that neurotrophic factors secreted from fetal kidney grafts stimulated both TH-positive neurons in the VM cografts and cholinergic neurons in the host striatum. Thus, these factors may be combined for treatment of degenerative diseases involving both dopaminergic and cholinergic neurons.

Studies of histogenetic and neurodegenerative processes in the nervous system using heterotopic neurotransplantation

The aim of the present article is to summarize our own experimental and published data on neurotransplantation into ectopic sites such as peripheral nerves (mainly) and the anterior chamber of the eye in rats. The review addresses questions touching on the following problems: the histogenesis and survival of nervous tissue after transplantation, the interaction between transplanted tissues with recipient tissues, assessment of long-term living transplants, simultaneous transplantation of different embryonic rudiments, transplantation of spinal cord ganglia, and the effects of trophic factors on the development of transplants. New data on stem cell transplantation into peripheral nerves are discussed.

Nerve growth factor in treatment and pathogenesis of Alzheimer's disease

The etiology of Alzheimer's disease (AD) is still unknown. In addition, this terrible neurodegenerative disease will increase exponentially over the next two decades due to longer lifespan and an aging "baby-boomer" generation. All treatments currently approved for AD have moderate efficacy in slowing the rate of cognitive decline in patients, and no efficacy in halting progression of the disease. Hence, there is an urgent need for new drug targets and delivery methods to slow or reverse the progression of AD. One molecule that has received much attention in its potential therapeutic role in AD is nerve growth factor (NGF). This review will demonstrate data from humans and animals which promote NGF as a potential therapeutic target by (1) outlining the hypothesis behind using NGF for the treatment of AD, (2) reviewing both the normal and AD altered signaling pathways and effects of NGF in the central nervous system (CNS), and (3) examining the results of NGF treatment obtained from animal models of AD and AD patients.