Fluorescence histochemistry of biogenic monoamines. A study of the capacity of various carbonyl compounds to form fluorophores with biogenic monoamines in gas phase reactions.
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Acetates↗
Biomedical subjects
O Lindvall
Publications and source records attributed to O Lindvall.
Recent progress in aldehyde fluorescence histochemistry.
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Animals↗
Improved catecholamine histofluorescence in the developing brain based on the magnesium and aluminum (ALFA) perfusion techniques: methodology and anatomical observations.
Detailed protocols for the application of two different metal salt perfusion procedures are described for the production of superior catecholamine histofluorescence in the brains of immature rats up to 2 weeks of age. As in the adult, both magnesium and aluminum salts are highly advantageous for catecholamine histofluorescence in developing animals, and yield marked increases in sensitivity. In the magnesium-perfusion technique, animals are perfused in a simple one-step process using a hand-held syringe with cold buffer containing magnesium sulphate, formaldehyde and glyoxylic acid. The aluminum-perfusion (ALFA) technique provides even greater sensitivity and richness of detail, but requires a controlled-pressure perfusion system and a two-step perfusion process. Animals are first perfused with a room-temperature buffer containing magnesium sulphate and procain (to prevent vasoconstriction) followed by cold buffer containing aluminum sulphate and formaldehyde. In both methods, tissue pieces are subsequently freeze-dried, reacted with formaldehyde vapour and paraffin-sectioned according to the standard Falck-Hillarp procedure. Tissue pieces can also be taken from aluminum-perfused brains for simultaneous catecholamine assay using radioenzymatic methods, thereby permitting correlated histochemical and neurochemical analyses on the same brains. Many catecholamine terminal systems can be visualized in the rat brain even at birth with the ALFA procedure following pargyline pretreatment. However, the endogenous intraaxonal catecholamine concentration is so low in immature brains that the full anatomical extent of these systems cannot be reliably seen without recourse to pre-loading with an exogenously administered amine. For this purpose systemic injections of alpha-methyl-noradrenaline were extensively investigated. In combination with the ALFA procedure, such pretreatment was found to cause a dramatic increase in both the intensity and number of terminal and preterminal fibers throughout the brain. Control experiments with 6-hydroxydopamine and the catecholamine uptake blocker, nomifensine, indicate that this loading is specific for catecholamine systems. This approach has indicated that certain of the forebrain noradrenergic and dopaminergic systems are very extensive at birth, and in some regions an intermediate stage of hyperinnervation is a normal feature of ontogeny. Some of these findings are illustrated here and will also be presented in greater detail in further reports.
Aging↗
Origin and termination of the diencephalo-spinal dopamine system in the rat.
Using a combination of neonatal 6-hydroxydopamine and adult 5,7-dihydroxytryptamine treatment we have been able to achieve a 94-99% depletion of noradrenaline in the spinal cord. In such animals the dopamine levels are only marginally affected in the dorsal horn (at all levels) and in the intermediate zone at thoraco-lumbar levels. This combined treatment thus offers new possibilities for selective studies of the spinal dopamine projection. In agreement with the biochemical data the fluorescence histochemistry shows that the spinal dopamine innervation is mainly confined to the dorsal horn, the intermediolateral cell column and associated parts of the intermediate and central gray. Injections of fluorescent retrograde tracer combined with monoamine fluorescence histochemistry reveal that the diencephalic A11 cell group is the principal, and perhaps exclusive, source of this innervation. The area of termination, as well as the organizational similarities with certain diencephalic peptide-containing projections to the spinal cord, suggest that the diencephalo-spinal dopamine system may be importantly involved in autonomic regulatory processes.
Animals↗
Fetal dopamine-rich mesencephalic grafts in Parkinson's disease.
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Brain↗
Expression of platelet-derived growth factor in and around intrastriatal embryonic mesencephalic grafts.
The expression of platelet-derived growth factor (PDGF) was investigated in the embryonic donor tissue and surrounding host brain before and after intracerebral transplantation in a rat model of Parkinson's disease (PD). Ventral mesencephalic tissue from E13-E15 rat embryos was dissociated and implanted into adult rats with unilateral lesions of the mesostriatal dopamine system. Immunohistochemical studies showed that the majority of the grafted cells were PDGF-positive at early time points after grafting. However, the immunostaining gradually decreased, and had disappeared almost completely 3 wk after transplantation. These results were in agreement with in situ hybridization data demonstrating detectable levels of mRNA for PDGF chains in graft cells after 1, but not after 6 wk. In contrast, a large number of PDGF-immunoreactive cells was observed in the host brain adjacent to the grafts from 1 wk after transplantation, and increasing with time. Increased expression of PDGF was also observed in response to a sham-operation (injection of vehicle), although the number of PDGF-positive cells seemed lower than after grafting of embryonic tissue. Double immunofluorescence labeling of these cells with an anti-glial fibrillary acidic protein (GFAP) antiserum and a monoclonal antibody against PDGF B-chain, indicated that the PDGF-positive cells were astrocytes. The dynamic expression of PDGF in and around intrastriatal embryonic mesencephalic implants has several, potentially important, implications for graft survival and function. Glial cells could utilize the elevated levels of PDGF to proliferate in a reactive gliosis, and PDGF might also augment immune responses. It is also possible that PDGF increases the survival of, and promotes neurite outgrowth from, grafted dopaminergic neurons.
Analysis of Variance↗
Platelet-derived growth factor receptor expression after neural grafting in a rat model of Parkinson's disease.
Platelet-derived growth factor (PDGF) has trophic effect on dopaminergic neurons in vitro. We have previously shown dynamic changes in the expression of PDGF in embryonic mesencephalic grafts and surrounding host striatal tissue following intracerebral transplantation in a rat model of Parkinson's disease. In this study the expression of the PDGF receptors was examined in the same model using immunohistochemistry. Most ventral mesencephalic (VM) cells from E13-E15 rat embryos possessed both PDGF alpha- and beta-receptors before implantation. Double immunofluorescence staining revealed that about 10% of the cells also expressed tyrosine hydroxylase (TH). The PDGF alpha-receptor was detectable in the graft up to 1 wk after transplantation but had disappeared at 3 wk. In the host tissue, scattered glial cells were positive for the alpha-receptor but the expression was unchanged following transplantation. The beta-receptor expression almost completely disappeared from the grafted tissue by 4 h following transplantation, and only a few cells of the host striatum showed immunoreactivity. However, after 3 wk beta-receptor positive cells were again detectable in the graft. These cells appeared to be endothelial cells as identified by an antibody against von Willebrand's factor. Our data suggest that PDGF might act locally on embryonic dopaminergic cells in an autocrine or juxtacrine manner before and shortly after transplantation, and on surrounding glial cells in a paracrine manner after transplantation. Furthermore, PDGF-BB might influence neovascularization in the graft.
Animals↗
Neural transplantation.
Cell transplantation is now being explored as a new therapeutic strategy to restore function in the diseased human central nervous system. Neural grafts show long-term survival and function in patients with Parkinson's disease but the symptomatic relief needs to be increased. Cell transplantation seems justified in patients with Huntington's disease and, at a later stage, possibly also in demyelinating disorders. The further development in this research field will require systematic studies in animal experiments but also well-designed clinical trials in small groups of patients.
Animals↗
Effects of hibernation or cryopreservation on the survival and integration of striatal grafts placed in the ibotenate-lesioned rat caudate-putamen.
Tissue storage prior to intracerebral transplantation would represent a major advantage when conducting clinical transplantation trials in that the procurement of the embryonic donor tissue and the timing of neurosurgery could be planned more efficiently. In the present study, the effects of storing rat embryonic striatal tissue at either +4 degrees C or below freezing temperature prior to grafting to the adult striatum, were assessed with regard to transplant survival, morphology and integration. Eleven days following a unilateral injection of ibotenic acid into the head of the caudate-putamen, a control group of rats received grafts of striatal primordium prepared immediately after dissection from rat embryos (embryonic day 16). A second group of rat embryonic striatal tissue was stored at 4 degrees C (hibernation) for 5 days and then transplanted. A third group of the striatal donor tissue was cryopreserved in liquid nitrogen for 5 days before implantation surgery. Six to seven weeks following transplantation surgery, the grafts were analysed in brain sections processed for acetylcholinesterase histochemistry, DARPP-32 (dopamine and cyclic AMP regulated phosphoprotein with a molecular weight of 32 kDa) and tyrosine hydroxylase (TH) immunocytochemistry. The mean total graft volume and the relative size of the AChE-positive regions were not significantly different between the three groups. Striatal-specific graft regions, positively stained for AChE and DARPP-32, generally exhibited TH immunoreactivity, suggesting that they had received dopaminergic afferents from the host brain. We conclude that embryonic rat striatal tissue can be cryopreserved or hibernated over 5 days without significant impairment in the yield of striatal neurons following intrastriatal implantation and without markedly affecting transplant morphology.
Acetylcholinesterase↗
Do tyrosine hydroxylase-immunoreactive neurons in the ventrolateral arcuate nucleus produce dopamine or only L-dopa?
Dopamine (DA) was early demonstrated in the arcuate nucleus by means of the formaldehyde-induced histofluorescence method. In the present study we have investigated the distribution of cell bodies in the arcuate nucleus with antisera against tyrosine hydroxylase (TH), aromatic L-amino acid decarboxylase (AADC) and DA. The results indicate that TH-immunoreactive cells in the dorsomedial part of the arcuate nucleus also contain immunoreactivity for both AADC and DA. However, TH-positive cells in the ventrolateral arcuate nucleus lacked AADC- and DA-immunoreactivity with the sensitivity of the present methods. The findings raise the question whether the ventrolateral cells synthesize L-DOPA or DA as endproducts.
Animals↗