Ferdinand Richard

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An improved quantitative immunochemical determination of brain tyrosine hydroxylase (TH) concentrations was designed using direct transfer into nitrocellulose from 20-microns thick brain sections, followed by immunodetection and quantitative radioautography in three reference brain structures (locus ceruleus, substantia nigra, and ventral tegmental area).(More)
The long-term changes in tyrosine hydroxylase (TH) activity induced by chronic exposure to cold in brain noradrenergic neurons of the locus coeruleus (LC) were analyzed and compared to those measured in a peripheral tissue such as adrenals. This analysis was made possible at the level of one single tissue corresponding to one animal by the use of sensitive(More)
An immunoblot procedure was developed to quantify the amount of tryptophan hydroxylase (TpOH), the rate limiting enzyme in the synthesis of serotonin, in the rat raphe dorsalis nucleus (NRD). Using this method we have studied the time course variations in TpOH protein level after a single p-chlorophenylalanine (PCPA) i.p. injection (300 mg/kg). PCPA(More)
The ontogenetic variations of tyrosine hydroxylase (TH) have been studied in locus coeruleus of developing rats. During the first 2 weeks after birth, a large increase in TH content (6.04-23.99 TH units) in the noradrenergic structure was observed, followed by a period of progressive increase of the protein concentration (42 TH units in adult rats). The(More)
The effects of RU24722 (14,15-dihydro-20,21-dinoreburnamine-14-ol) on tyrosine hydroxylase in central catecholaminergic neurons were studied in rats treated with different quantities of the molecule, and a time course was done for the minimal dose that gave the maximal effect. RU24722 induced increases in tyrosine hydroxylase activities and specific protein(More)
Distribution of tryptophan-5-hydroxylase (TpOH)-containing cells and TpOH protein tissue concentrations were evaluated in the nucleus raphe dorsalis (NRD) of rat brain by immunocytochemistry and direct transfer onto nitrocellulose filters of unfixed adjacent brain sections. This work has demonstrated that: (1) the direct transfer onto nitrocellulose filters(More)
Catecholamine metabolism was studied in vivo in the C1 adrenergic area of the rostral ventrolateral medulla oblongata in rats, using differential normal pulse voltammetry coupled with an activated carbon fiber microelectrode. Pharmacological evidence indicates that 3,4-dihydroxyphenylacetic acid, the major dopamine metabolite, is responsible for the(More)
RU24722, as a racemic mixture, has been found to act on neuronal activity and the long-term regulation of tyrosine hydroxylase in the locus coeruleus of the rat. In this study, the effects of two enantiomeric derivatives of RU24722 (3 alpha and 16 alpha forms), as compared to the racemic form itself, are studied. The short-term effect was estimated 20 min(More)
The effects of different potassium channel blockers on tritiated dopamine [( 3H]DA) release were investigated in rat striatal slices in the presence of pargyline and nomifensine (10 microM each). 4-Aminopyridine (4-AP; 10 and 30 microM) and 3,4-diaminopyridine (3,4-DAP; 30 microM) markedly increased the basal tritium outflow, whereas tetraethylammonium(More)