GABA mimetics increase extracellular DOPAC (as measured by in vivo voltammetry) in the rat locus coeruleus

1986 ◽  
Vol 332 (4) ◽  
pp. 380-383 ◽  
Author(s):  
B. Scatton ◽  
A. Serrano
Keyword(s):  
Locus Coeruleus ◽  
In Vivo Voltammetry ◽  
Gaba Mimetics

Fentanyl decreases catecholamine metabolism measured by in vivo voltammetry in the rat locus coeruleus

1989 ◽  
Vol 67 (5) ◽  
pp. 532-536 ◽  
Author(s):  
Brian Milne ◽  
Luc Quintin ◽  
Jean Yves Gillon ◽  
Jean-François Pujol
Keyword(s):  
Carbon Fiber ◽  
Locus Coeruleus ◽  
Catecholamine Metabolism ◽  
In Vivo Voltammetry ◽  
Oxidation Current ◽  
Arterial Blood ◽  
Carbon Fiber Electrodes ◽  
Current Maximum ◽  
Catechol Oxidation

The objective of this study was to investigate under controlled conditions the effects of fentanyl on the rat locus coeruleus catechol oxidation current. Using differential normal pulse voltammetry combined with electrochemically treated carbon fiber electrodes to measure the catechol oxidation current, catecholamine metabolism can be reliably monitored. Male Sprague–Dawley rats weighing 500–600 g had carbon fiber electrodes implanted into the locus coeruleus under halothane – O2 – air anesthesia with controlled ventilation and muscle relaxation. Experiments consisted of four groups of rats given the following treatments: (A) saline (n = 6); (B) fentanyl, 10 μg∙kg−1 i.v. (n = 6); (C) naloxone, 800 μg∙kg−1 i.v. followed 2 min later by fentanyl, 10 μg∙kg−1 (n = 5); (D) clonidine, 200 μg∙kg−1 i.p. (n = 6). There was no significant change in the catechol oxidation current following saline. Fentanyl produced a significant (ANOVA, p < 0.05) decrease in the catechol oxidation current (maximum 32 min postinjection was 75.8 ± 4.6% of baseline). This decrease was prevented by a prior injection of naloxone. Clonidine produced a significant decrease in catechol oxidation current (maximum 40 min postinjection was 54.1 ± 7.0% of baseline). Systolic blood pressure was significantly decreased following clonidine and there were no significant changes in arterial blood gases throughout the experiments. The α2-adrenergic agonist clonidine and the opioid fentanyl produced a decrease in locus coeruleus catechol oxidation current measured by in vivo voltammetry, which monitors catecholamine turnover.Key words: catecholamine, clonidine, fentanyl, opiates, locus coeruleus, in vivo voltammetry.

Noradrenergic turnover increases in locus coeruleus after hemorrhage in cats

1988 ◽  
Vol 254 (2) ◽  
pp. R296-R301
Author(s):  
K. V. Thrivikraman ◽  
D. E. Carlson ◽  
D. S. Gann
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Locus Coeruleus ◽  
High Performance ◽  
In Vivo Voltammetry ◽  
Oxidation Current ◽  
Alpha Chloralose ◽  
Catecholamine Oxidation ◽  
Acth Release

Push-pull perfusion was used to determine monoaminergic activity in the locus coeruleus (LC) of alpha-chloralose-urethan-anesthetized cats after 20% hemorrhage. Blood was withdrawn from 0 to 3 min and reinfused from 10 to 13 min. Continuous 5-min interval samples of perfusate were collected from -5 to 15 min. Concentrations of the monoamines were determined using high-performance liquid chromatography with electrochemical detection. The perfusion sites (n = 21) were identified histologically. In a group of eight contiguous sites in the ventral LC (vLC), 4-hydroxy-3-methoxy-phenyl(ethylene)glycol (MHPG) increased significantly from 0.50 +/- 0.22 (control) to 1.19 +/- 0.42 pmol/5 min during the first 5 min after hemorrhage (P less than 0.05). This response differed significantly from that obtained at the remaining 13 sites. Other metabolites were not often detectable for many sites either within or outside vLC, and their responses to hemorrhage were not significant. The response of MHPG in the vLC indicates that norepinephrine (NE) turnover increases in this area selectively and implicates NE in the increase in the catecholamine oxidation current reported previously using in vivo voltammetry. Since the vLC was shown previously to facilitate adrenocorticotropin (ACTH) release, the increase in NE turnover after hemorrhage could induce ACTH release. This increase may also act locally to modulate the ascending hemodynamic signal.

Cholinergic control of catechol metabolism in the rat locus coeruleus as studied by in vivo voltammetry

1983 ◽  
Vol 95 (1-2) ◽  
pp. 65-70 ◽  
Author(s):  
Maria Grazia de Simoni ◽  
François Gonon ◽  
Michel Buda ◽  
Jean François Pujol
Keyword(s):  
Locus Coeruleus ◽  
In Vivo Voltammetry

In Vivo Voltammetry and Microdialysis Monitoring of Monoamine Metabolism in the Rat Brainstem Neurons

1995 ◽  
Vol 17 (1-2) ◽  
pp. 129-140 ◽  
Author(s):  
L. Lambás Sen¯as ◽  
C. Vachette ◽  
F. Robert ◽  
C. Ortemann ◽  
B. Renaud
Keyword(s):  
Monoamine Metabolism ◽  
In Vivo Voltammetry ◽  
Rat Brainstem
Sign in / Sign up

Export Citation Format

Share Document