Striatal tyrosine hydroxylase activity: multiple conformational kinetic oscillators and product concentration frequencies

Striatal tyrosine hydroxylase activity: multiple conformational kinetic oscillators and product concentration frequencies.

Samples from rat striate cortices, taken in triplicate at 2-min intervals from a supernatant maintained at 4 degree C, then assayed for 1 min at 37 degree C for tyrosine hydroxylase activity, manifested average amplitudes of time-dependent variation that were related to the level of mean velocity and were not influenced by changing temperature or pharmacological ligands. In contrast, the freque...

Are striatal tyrosine hydroxylase interneurons dopaminergic?

Striatal GABAergic interneurons that express the gene for tyrosine hydroxylase (TH) have been identified previously by several methods. Although generally assumed to be dopaminergic, possibly serving as a compensatory source of dopamine (DA) in Parkinson's disease, this assumption has never been tested directly. In TH-Cre mice whose nigrostriatal pathway had been eliminated unilaterally with 6-...

Dopaminergic and cholinergic modulation of striatal tyrosine hydroxylase interneurons.

The recent electrophysiological characterization of TH-expressing GABAergic interneurons (THINs) in the neostriatum revealed an unexpected degree of diversity of interneurons in this brain area (Ibáñez-Sandoval et al., 2010, Unal et al., 2011, 2015). Despite being relatively few in number, THINs may play a significant role in transmitting and distributing extra- and intrastriatal neuromodulator...

Dephosphorylation of purified brain tyrosine hydroxylase by rat striatal extracts.

Tyrosine hydroxylase (TH) was purified from bovine brain and enzymatically phosphorylated in vitro. Radioactively phosphorylated TH was dephosphorylated by rat tissue extracts. Of tissues examined, rat corpus striatal extracts were highest in specific activity in the TH dephosphorylating assay. Phosphorylated histone did not inhibit dephosphorylation of TH by rat striatal extracts. The thermal ...

Presynaptic regulation of tyrosine hydroxylase activity in rat striatal synaptosomes by dopamine analogs.