Refine
Has Fulltext
- yes (107)
Is part of the Bibliography
- yes (107)
Year of publication
- 1989 (107) (remove)
Document Type
- Journal article (107) (remove)
Keywords
- Anorganische Chemie (9)
- Organische Chemie (9)
- Toxikologie (7)
- Psychologie (6)
- Infektionsbiologie (5)
- Neurobiologie (5)
- Biochemie (4)
- Biologie (4)
- Kind (4)
- Physiologische Chemie (3)
Institute
- Theodor-Boveri-Institut für Biowissenschaften (21)
- Institut für Molekulare Infektionsbiologie (10)
- Institut für Organische Chemie (10)
- Institut für Anorganische Chemie (9)
- Institut für Pharmakologie und Toxikologie (9)
- Institut für Psychologie (7)
- Institut für Psychologie (bis Sept. 2007) (6)
- Neurochirurgische Klinik und Poliklinik (6)
- Institut für Klinische Neurobiologie (4)
- Institut für Pädagogik (bis Sept. 2007) (4)
Ciliary neurotrophic factor (CNTF) influences the levels of choline acetyltransferase (ChAT) and tyrosine hydroxylase (TH) in cultures of dissociated sYmpathetic neurons from newborn rats. In the presence of CNTF both the total and specific activity of ChAT was increased 7 d after culture by 15- and 18-fold, respectively, as compared to cultures kept in the absence of CNTF. Between 3 and 21 d in culture in the presence of CNTF . the total ChAT activity increased by a factor of >100. Immunotitration demonstrated that the elevated ChAT levels were due to an increased number of enzyme molecules. In contrast to the increase in ChAT levels, the total and specific activity levels' of TH were decreased by 42 and 36 %, respectively, after 7 d in culture. Half-maximal effects for both ChAT increase and TH decrease were obtained at CNTF concentrations of rvO.6 ng and maximal levels were reached at I ng of CNTF per milliliter of medium. The effect of CNTF on TH and ChAT levels were seen in serum-containing medium as well as in serum-free medium. CNTF was shown to have only a small effect on the long-term s.urviVal of rat sympathetic neurons. We therefore concluded that the effects of CNTF on ChAT and TH are not due to selective survival of cells that acquire cholinergic traits in vitro, but are rather due to the induction of cholinergic differentiation of noradrenergic sympathetic neurons.
Vorwort (Das Kind (1989) 5)
(1989)
No abstract available
Vorwort (Das Kind (1989) 6)
(1989)
No abstract available
No abstract available
Observations on captive reed frogs Hyperolius viridijlavus ommatostictus showed that seven out of 24 females changed into males. Sex change occurred without any hormone treatment and resulted in completely functional males. The adaptive value is discussed in terms of maximizing life-time reproductive success. Hyperolius r. ommatostictus is the first amphibian known to show functional sex reversal.
At early developmental stages (embryonic day 7, E7), chick paravertebral sympathetic ganglia contain a cell population that divides in culture while expressing various neuronal properties. In an attempt to identify factors that control neuronal proliferation, we found that ciliary neurotrophic factor (CNTF) specifically inhibits the proliferation of those cells expressing neuronal markers. In addition, CNTF affects the differentiation of sympathetic ganglion cells by inducing the expression of vasoactive intestinal peptide immunoreactivity (VIP-IR). After 1 day in culture, tyrosine hydroxylase immunoreactivity (TH-I R) was expressed by about 86% of the cells whereas VIP-IR was virtually absent. In the presence of CNTF, 50%-60% of the cells expressed VIP-IR after 4 days in culture; however, none of the cells expressed VIP-IR in the absence of CNTF. These results, and the demonstration of cells that express both VIP and TH-IR, indicate that VIP is induced in cells that initially express tyrosine hydroxylase. The findings suggest a potential role for CNTF as a factor affecting the proliferation and differentiation of developing sympathetic neurons.
CILIARY neurotrophic factor (CNTF) was originally characterized as a survival factor for chick ciliary neurons in vitro. More recently, it was shown to promote the survival of a variety of otherneuronal cell types and to affect the differentiation of E7 chick sympathetic neurons by inhibiting their proliferation and by inducing the expression of yasoactiYe intestinal peptide immunoreactiyity (VIP-IR). In cultures of dissociated sympathetic neurons from newborn rats, CNTF induces cholinergic differentiation as shown by increased levels of choline acetyltransferase (ChAT.
No abstract available