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1.
The developmental variations of tyrosine hydroxylase (TH) and of acetylcholinesterase (AChE) were studied in embryonic and post-hatching chicken sympathetic ganglia. Different levels of TH activity were found in two different flocks of White Leghorn chicken, which are probably dependent on genetic differences. These enzymatic differences, however, do not become apparent before hatching and may indicate a combined effect of genetic variation and functional demands. During the period of incubation, TH activity is characterized by a pronounced and steady increase from the twelfth day of incubation up to day 2 after hatching. This corresponds to a period of intense maturation of the sympathetic neuron. In the period following hatching, the 'fourth day fall phenomenon' previously described by us for DOPA decarboxylase (DDC), dopamine-beta-hydroxylase (DBH), and monoamine oxidase (MAO) is not seen in the TH curve. Instead, TH activity tends to remain constant between days 2 and 14 after hatching (ah). Both ganglionic protein and weight remain constant in this period, indicating a phase of general pause in protein synthesis. AChE activity increases steadily from the eighth until the twenty-first day of incubation. A sudden and significant drop in AChE activity was found at day 2 ah followed by a period of rapid increase at day 3 ah and a levelling of activity up to day 30 ah. Comparing the present variations to those observed in our previous studies on DBH, a temporal relationship between TH and DBH activity is observed during the phases of synaptogenesis and maturation but not during the phase of intense functional activity. Our results strongly suggest that before hatching in chick embryo sympathetic ganglia, the cholinergic presynaptic terminals play a role in regulating the development of the adrenergic neurons. In the period following hatching, however, the DBH and TH levels in cell bodies seem to be principally regulated by the functional activity. This results in depletion of DBH, but not TH, through liberation along with the neurotransmitter at the periphery. Depletion of DBH at the terminals may result in increased transport and thereby depletion in the cell body. This mechanism is probably responsible for the difference in the profiles of activity of DBH and TH in the cell bodies observed in the first week after hatching.  相似文献   

2.
A single dose of reserpine administered into the yolk sac of chicken eggs prior to incubation produces two distinct periods of significant increase in tyrosine hydroxylase (TH) activity over controls. The first period is 21 days of incubation (55%) and the second is between day 14 and 30 after hatching (a.h.) (69%). Cholineacetyltransferase (ChAc) and dopadecarboxylase (DDC) are not modified in the two periods of increased TH activity. Reserpine had no effect on cholinergic parasympathetic synapses and neurons in the ciliary ganglion, as judged by ChAc activity. When reserpine was acutely administered in three different posthatching periods only the injection at the latest period (days 26 and 27) caused a significant (38%) increase in TH activity at day 30. Postsynaptic nicotinic receptors were blocked selectively by injecting chlorisondamine in the chick starting at hatching for one week. The administration of chlorisondamine almost completely abolished the reserpine induced increase of TH activity at day 15 a.h. The present results support the view that the development of enzyme activities specifically related to neurotransmitter biosynthesis in chick autonomic ganglia is regulated not only by transsynaptic influences but also by regulatory inputs originating in the periphery.  相似文献   

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We have studied the expression of catecholaminergic and cholinergic phenotypes in sympathetic ganglia removed from 7- to 10-day-old quail embryos and grown in vitro under different conditions. Quantitative data were obtained by measuring the conversion of (3H) tyrosine and (3H) choline to catecholamines (CA) and acetylcholine (ACh), respectively. In explant cultures, large amounts of both neurotransmitters were synthesized from the onset, but CA generally predominated, the molar ratios of CA:ACh being, on average, of the order of 2:1. If the ganglia were dissociated before plating, there was a selective increase in ACh synthesis (three- to fivefold) such that the CA:ACh ratio fell strikingly. The early expression of the cholinergic phenotype appears to be species-specific in that, under identical conditions, dissociated cell cultures of newborn mouse superior cervical ganglia were overwhelmingly catecholaminergic (CA:ACh ratio of approximately 40:1) and ACh synthesis was only just detectable. Addition of veratridine (1.5 μM) either to explant or to dissociated cell cultures of embryonic quail sympathetic ganglia barely altered CA-synthesizing ability; in contrast, ACh synthesis and accumulation were stimulated about threefold. This effect, which we found to correspond to a quantitatively similar increase in the activity of choline acetyltransferase (ChAT), was completely blocked by tetrodotoxin, indicating that it was due to Na+-dependent depolarization. A preferential stimulation of ACh production was also observed when the concentration of K+ was raised to 20 mM. Veratridine treatment of cultures of presumptive sympathoblasts, in the form of sclerotome-associated neural crest cells, had identical effects. Our results reveal the quantitative importance of ACh-related properties in avian sympathetic ganglia from the earliest stages of their development and suggest that depolarization may be one of the factors selectively enhancing expression of the cholinergic phenotype during ontogeny. In these respects, the neurochemical differentiation of sympathetic neurons unfolds according to dissimilar scenarios in birds and mammals. © 1993 Wiley-Liss, Inc.  相似文献   

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M Quik  J M Trifaró 《Brain research》1982,244(2):331-336
alpha-Bungarotoxin has been proposed to interact with a membrane site in neuronal tissue which has the characteristics of a nicotinic acetylcholine receptor and also a trophic receptor. A nerve cell function which is affected by both nicotinic stimulation and nerve growth factor is the induction of tyrosine hydroxylase. For this reason, alpha-bungarotoxin was tested on the carbachol-induced increase and nerve growth factor-mediated increase in tyrosine hydroxylase activity in two preparations of neuronal origin, organ cultures of rat superior cervical ganglia and cultured bovine adrenal medullary cells. The results demonstrate that the alpha-bungarotoxin site is not involved in tyrosine hydroxylase induction.  相似文献   

9.
Human personality characteristics and vulnerability to psychopathology are to a large extent dependent upon genetic factors which have yet to be fully defined. The allele distribution of the dopamine D4 receptor (D4DR) and thrombocyte monoamine oxidase (trbc MAO) activity have both been associated with personality traits which are supposedly related, namely 'sensation seeking’according to Zuckerman and‘novelty seeking’according to Cloninger, respectively. In this report, the D4DR allele distribution and trbc MAO activity were studied in 31 psychiatric patients and 21 control subjects. Trbc MAO activity is a biochemical marker of personality that has been shown to be under strong genetic influence. However, no association between the D4DR alleles and trbc MAO could be observed in this material. To our knowledge, this is the first report comparing these two markers, and based upon the results obtained, we speculate that they may be connected with different types of overlapping personality characteristics. The allele distribution of the tyrosine hydroxylase (TH) gene was also determined. TH is the rate-limiting enzyme in the biosynthesis of catecholamines, and it is believed to be involved in different kinds of psychopathology. No covariation between TH gene alleles and trbc MAO activity or D4DR alleles was observed in this material.  相似文献   

10.
Neural crest cells are the embryonic progenitors of several adult cell types, including some neurons that contain the neuroactive peptide somatostatin. To begin to understand the control of peptide expression during neuronal ontogeny, we have investigated the development of somatostatin-like immunoreactivity (SLI) in embryonic quail paravertebral sympathetic ganglia in vivo. SLI was identified by immunohistochemistry in paraformaldehyde-fixed cryostat sections from the trunk region of quail embryos. SLI was first observed in the cells of the primary sympathetic trunks at stage 18 (Zacchei, A.M. (1961) Arch. Ital. Anat. Embriol. 66:36-62), which corresponds to embryonic day 4 (E4). The primary sympathetic trunks are the sites of the initial aggregation of neural crest cells to form the sympathetic ganglia. The SLI in these cells was located in the cytoplasm and was absent from the nucleus. SLI persisted in subsequent developmental stages as formation of the definitive sympathetic ganglia occurred. At stage 23 (E7), when the lumbosacral paravertebral sympathetic ganglia have reached their definitive location, some cells in the ganglia contained SLI, and they were often located adjacent to one another. During the later stages of embryogenesis, sympathetic ganglia can be dissected from the embryo and the SLI content determined by radioimmunoassay. The amount of SLI is several-fold higher in ganglia removed at stage 23-24 (E7-8) than in ganglia removed at stage 26-27 (E9-10) or stage 31-32 (E13-14). This decline in SLI content reflects an absolute decrease per ganglion and is not solely due to the growth of tissue devoid of SLI.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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Optimal nerve growth factor (NGF) and potassium concentrations for the culture of explants of single chick embryo sympathetic ganglia in Leighton tubes are described.

NGF increases ganglionic monoamine oxidase (MAO; E.C. 1.4.3.4) activity in a dose dependent fashion with maximum effects at a concentration of about 8 U/ml NGF. Peak activity compares closely with values seen in chick gangliain vivo. Potassium-induced depolarization (45mM K+) also increases MAO activity; but the extent of the increase depends upon NGF concentration, for there is little or no increase at high NGF concentrations. Dibutyryl adenosine 3′,5′-cyclic monophosphoric acid (db cyclic AMP) can mimic the potassium-induced increase in MAO.  相似文献   


14.
We report here that S-100 beta, a protein with neurotrophic activity on central nervous system neurons, stimulates neuritic outgrowth from cultures of dorsal root ganglia (DRG). S-100 beta elicited neurites from explant and dissociated cell cultures of embryonic chick DRG, and the extent of the response varied with the age of the embryo. Specificity was demonstrated by the observation that incubation of S-100 beta with antibodies directed against S-100 beta reduced the neurite outgrowth, whereas incubation of S-100 beta with normal rabbit serum had little effect. S-100 beta also stimulated the area of neuritic outgrowth from organotypic cultures of fetal rat DRG, showing that the activity of the protein is not restricted to a particular species or culture condition. A mutant S-100 beta lacking neurotrophic activity on cerebral cortex neurons was unable to effectively stimulate neurite outgrowth from DRG cultures. These studies suggest that S-100 beta may play a role in neuronal growth and/or maintenance in the peripheral nervous system.  相似文献   

15.
α-Bungarotoxin has been proposed to interact with a membrane site in neuronal tissue which has the characteristics of a nicotinic acetylcholine receptor and also a trophic receptor. A nerve cell function which is affected by both nicotinic stimulation and nerve growth factor is the induction of tyrosine hydroxylase. For this reason, α-bungarotoxin was tested on the carbachol-induced increase and nerve growth factor-mediated increase in tyrosine hydroxylase activity in two preparations of neuronal origin, organ cultures of rat superior cervical ganglia and cultured bovine adrenal medullary cells. The results demonstrate that the α-bungarotoxin site is not involved in tyrosine hydroxylase induction.  相似文献   

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Dorsal root ganglia (DRG) from quail embryos of 10-15 days of incubation (E10-15) contain a subpopulation of cells, distinct from postmitotic neurons, that can, under suitable conditions of culture in vitro, differentiate into neuron-like cells that display a variety of adrenergic properties, including tyrosine hydroxylase (TH) immunoreactivity (Xue et al., Proc. Natl. Acad. Sci. U.S.A., 82 (1985) 8800-8804). The present study was undertaken to determine whether other markers typical of autonomic sympathetic nerve cells are also expressed in the same system. Cells immunoreactive for vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY) were found to differentiate continually from non-dividing precursors in all cultures of dissociated E10 quail DRG grown in the presence of chick embryo extract. Whereas VIP was already present (in a minute number of cells) in DRG in situ, NPY could not be detected before 3 days of culture, when it appeared simultaneously with TH. Double immunostaining experiments showed that most VIP-positive cells and about half the NPY-positive cells also displayed TH-immunoreactivity. On the other hand, there was no overlap between the substance P-containing neuronal population and any of the cells containing TH, NPY or VIP. These observations are pertinent to the problem of the segregation of autonomic and sensory cell lines during peripheral nervous system ontogeny.  相似文献   

17.
A new method has been developed for the preparation of essentially pure primary cultures of neurons and non-neuronal cells from 11-day embryonic chick sympathetic ganglia. This method utilizes (1) differences in cell-to-substrate adhesiveness between neurons and non-neuronal cells and (2) the capacity of neurons to form homotypic aggragates. The maximum difference in adhesiveness between neuronal and non-neuronal cells occurred when the ganglia were dissociated with trypsin following collection in a salt solution lacking divalent cations. This difference allowed the preparation of highly purified non-neuronal cultures and 85–90% pure neuronal cultures. Intermittent agitation during the period of cell separation markedly increased the purity of the neuronal cultures by (1) inhibiting neuronal but not non-neuronal cell attachment and (2) facilitating the formation of homotypic neuronal aggregates in the supernatant. Neuronal and non-neuronal cultures prepared under these conditions were more than 99% pure on the basis of both morphological and biochemical analyses. Both cell types exhibited attachment efficiences greater than 95% and have been maintained for several weeks in vitro. Thus, completely isolated neuronal and non-neuronal cultures can be prepared and maintained for prolonged periods in the absence of cells of the other type.  相似文献   

18.
Toxic damage of brain cells by aluminium (A1) is discussed as a possible factor in the development of neurodegenerative disorders in humans. To investigate neurotoxic effects of A1, serum-free cultures of mechanically dissociated embryonic chick (stage 28–29) forebrain, brain stem and optic tectum, and for comparison meningeal cells, were treated with A1 (0–1000 M) for 7 days. Effects of A1 on cell viability (lysosomal and mitochondrial activity) and differentiation (synthesis of cell-specific proteins) were found to the brain area specific with the highest sensitivity observed in optic tectum. No inhibiting effects on cell viability could be observed in cultures of forebrain and meninges in the concentration range tested. In all three brain tissue cultures, threshold levels for the reduction of cell differentiation parameters were found at lower concentrations [concentration resulting in a 50% decrease (IC50)>180 M] than for the inhibitionof cell viability (IC50>280 M) indicating a specific toxic potential of A1 for cytoskeletal alterations. The culture levels of nerve cellspecific markers microtubule-associated protein type 2 (the most sensitive parameter) and the 68-kDa neurofilament were inhibited at lower concentrations (IC50 180–630 M) than the astrocyte-specific glial fibrillary acidic protein (IC50 700–1000 M), demonstrating a particularly high sensitivity of neurons in comparison to astrocytes. Based on these differences in A1 sensitivity observed for different cell markers in the various brain tissue cultures, the in vitro system used in the present study proved to be a suitable model to assess brain area and cell type-specific neurotoxic effects of A1.This study is part of the Ph. D. thesis of Judith P. Mueller.Preliminary results were presented at the 24th Annual Meeting of the Swiss Societies for Experimental Biology (USGEB/USSBE)  相似文献   

19.
Assay of microtuble protein in embryonic chick dorsal root ganglia   总被引:4,自引:0,他引:4  
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