We have studied the regulation of tyrosine hydroxylase by cell-cell contact in primary cultures of bovine adrenal chromaffin cells. Preparation of dissociated chromaffin cells from bovine adrenal medullae or the harvesting of cultured cells resulted in a rapid decrease of the specific mRNA(TH) (defined as the amount of mRNA(TH) (where TH represents tyrosine hydroxylase) per microgram of total R...

Dopaminergic lesions result in the acute loss of striatal dopamine content, the loss of tyrosine hydroxylase-immunoreactive fibers, upregulation of preproenkephalin mRNA expression, and compensatory changes in the synthesis and metabolism of dopamine. Despite the severe loss of fine tyrosine hydroxylase-immunoreactive fibers, larger fibers persist. We found that some tyrosine hydroxylase fiber ...

Neural stem cells (NSCs) as a heterogeneous multipotent and self- renewal population are found in different areas in the developing mammalian nervous system, as well as the sub-ventricular zone (SVZ) and the hippocampus of the adult brain. NSCs can give rise to neurons, astrocytes and oligodendrocytes. The aim of this study was to differentiate neural stem cells into noradrenergic–like cells in...

It has been reported that the administration of cycloheximide, a protein synthesis inhibitor, depresses brain tyrosine hydroxylase activity as measured in vitro. This finding raised the possibility that the amnesic effect of this drug could be due to reduction of norepinephrine synthesis rather than to inhibition of protein synthesis required for long-term memory. We have found that (1) amnesic...

The transport of norepinephrine and two key enzymes involved in its synthesis, tyrosine hydroxylase (EC 1.14.3a) and dopamine beta-hydroxylase (EC 1.14.2.1), has been studied in relation to other axonal constituents in ligated chicken sciatic nerves. Norepinephrine, tyrosine hydroxylase, and dopamine beta-hydroxylase activity all increased proximal to the constriction over a 20-hr period. The r...

Tyrosine hydroxylase activity of synaptosomes isolated from rat brain was examined. A modified tritium-displacement assay was used, which allowed the measurement of tyrosine hydroxylase activity without the addition of either inhibitors of the metabolism of the hydroxylated products or added exogenous cofactor. The enzyme activity was strongly inhibited by the addition of exogenous catecholamin...

Tyrosine hydroxylase is synthesized de nouo in rat superior cervical ganglia in organ culture. The differential rate of synthesis is not increased significantly by the addition of nerve growth factor to the culture. Prior administration of nerve growth factor in vim. however, leads to an augmented synthesis of tyrosine hydroxylase in ganglia subsequently cultured in vitro. The differential rate...

Loss-of-function DJ-1 mutations have been linked to autosomal recessive early-onset Parikinsonism. However, the putative function of DJ-1 is not completely understood. Previous studies indicate that DJ-1 overexpression results in upregulation of the tyrosine hydroxylase gene. The mechanism by which DJ-1 affects tyrosine hydroxylase expression remains elusive. In the present study, we show that ...

Tyrosine hydroxylase is synthesized de novo in rat superior cervical ganglia in organ culture. The differential rate of synthesis is not increased significantly by the addition of nerve growth factor to the culture. Prior administration of nerve growth factor in vivo, however, leads to an augmented synthesis of tyrosine hydroxylase in ganglia subsequently cultured in vitro. The differential rat...

Neural stem cells (NSC) with self-renewal and multilineage potential are considered good candidates for cell replacement of damaged nervous tissue. In vitro experimental conditions can differentiate these cells into specific neuronal phenotypes. In the present study, we describe the combined effect of basic fibroblast growth factor (bFGF) and dibutyryladenosine 3',5'-cyclic monophosphate (dbcAM...