Showing papers by "Efrain C. Azmitia published in 1988"
Journal Article•
TL;DR: It is suggested that purified laminin can facilitate and guide process outgrowth of 5-HT, DA and NE neurons during early developmental stage, but does not induce sprouting on these same fiber types in the adult brain.
36 citations
TL;DR: Parachlorophenylalanine or 5-methoxytryptamine was administered to pregnant Sprague Dawley rats from day 8 of gestation till D17 and from D12 until birth respectively and both drug groups of neonates showed deficits: less activity, less alternation, and less avoidance.
Abstract: Parachlorophenylalanine (pCPA) or 5-methoxytryptamine (5MT) was administered to pregnant Sprague Dawley rats from day 8 (D8) of gestation till D17 and from D12 until birth respectively. Birth weights of both drug groups of neonates were approximately 20% less than the saline-injected controls. 5MT neonates showed a significant reduction of high affinity 3H-5HT uptake in the brainstem at all three time points: D1, D15, D30, and a slight reduction in the forebrain reaching significance only on D30. The pCPA animals showed a significant reduction in the brainstem and forebrain on D1 and D30, but only a small nonsignificant reduction in both areas on D15. Behaviors measured on day 15 revealed that in general activity, spontaneous alternaton, and passive avoidance both drug groups of neonates showed deficits: less activity, less alternation and less avoidance.
27 citations
TL;DR: This multilevel analysis provides the reader with an overview of the events regulating neuronal survival, differentiation and death and an understanding of these basic questions is necessary to sequence the molecular events resulting in neuronal death.
23 citations
TL;DR: The results presented in this chapter are consistent with the hypothesis that laminin provides adhesion for neuronal attachment and promotes neurite outgrowth, and may prove to be clinically significant.
Abstract: Publisher Summary Laminin is a strong adhesive glycoprotein present in basement membrane, where it provides attachment for many cell types. This chapter describes and provides direct evidence that laminin has effects on neurite outgrowth of developing neurons in vivo , and demonstrates that laminin can be applied to increase fiber outgrowth of transplanted neurons and to guide the growing fibers in a given target direction, using transplantation of fetal neurons. The hypothesis of neuronal migration guided by glia in the cerebellum may be mediated by laminin, which is produced by glia in the cerebellum during development. The results presented in this chapter are consistent with the hypothesis that laminin provides adhesion for neuronal attachment and promotes neurite outgrowth. Laminin placed in the brain evidently provides preferential adhesion for developing neurons and their extending fibers. Laminin may prove to be clinically significant, as it can provide a means to stimulate and direct the growth of neuronal systems into selected target areas.
19 citations
TL;DR: Changes in the innervation pattern and 5-HT level in the dorsal hippocampus occur following transplantation of fetal tissue are discussed and suggest that both the target tissue and afferent neurons readjust to accommodate extrinsic transplanted tissue.
19 citations
TL;DR: The chapter indicates that given the existing limitation of resolution of electrophysiological techniques in the in vitro slice preparation, the heterogeneity of grafted tissue and synapse formation with selective populations of host neurons, the graft should be useful for examining basic questions relevant to central neurotransmission.
Abstract: Publisher Summary The transplanted tissue can promote local processes of regeneration, prevent retrograde degeneration, or simply serve as a slow-release biological capsule, which discharges the appropriate neurotransmitter in a random fashion into the intercellular space. This chapter describes the physiology of graft-host interactions in the rat hippocampus. The chapter also addresses two main questions that guide the research on the physiology of graft-host interactions, (1) can the graft substitute for the damaged host tissue, be incorporated into host circuits and function as expected of a normal host tissue; and (2) can the graft serve as a simple model system for asking questions relevant to normal brain operation. Independent of the possible restoration of functions, the graft can be used as a simple model for complex networks in the brain. The chapter indicates that given the existing limitation of resolution of electrophysiological techniques in the in vitro slice preparation, the heterogeneity of grafted tissue and synapse formation with selective populations of host neurons, the graft should be useful for examining basic questions relevant to central neurotransmission.
8 citations
01 Jan 1988
TL;DR: In this article, procedures for the preparation of the fetal cells to insure best survival and methods to identify transplanted neurons whose neurotransmitter content is known are discussed. And several strategies for reducing the glial scar, enhancing fetal cell survival (co-transplantation), inducing host brain trophic factors (prior lesions or preparation of a soluble extract) and providing adhesive molecules to encourage outgrowth.
Abstract: If transplanted fetal cells are to have maximal benefits in the adult brain, the donor and host neurons must fully interact. In this report, we have discussed procedures for the preparation of the fetal cells to insure best survival and methods to identify transplanted neurons whose neurotransmitter content is known. Furthermore, we provide several strategies for reducing the glial scar, enhancing fetal cell survival (co-transplantation), inducing host brain trophic factors (prior lesions or preparation of a soluble extract) and providing adhesive molecules to encourage outgrowth. Many additional strategies need to be developed to produce an optimal integration of fetal and adult cells. Once achieved, brain transplantation can provide a powerful and unparalleled tool to regulate cell function and combat diseases.