Intracerebral microinjection of stannous 2-ethylhexanoate affects dopamine turnover in cerebral cortex and locomotor activity in rats

2008 ◽  
Vol 87B (2) ◽  
pp. 381-386 ◽  
Author(s):  
Takashi Yamada ◽  
Duk-Young Jung ◽  
Rumi Sawada ◽  
Toshie Tsuchiya
Keyword(s):  
Cerebral Cortex ◽  
Locomotor Activity ◽  
Dopamine Turnover ◽  
Intracerebral Microinjection

scholarly journals Monoaminergic Involvement in Decreased Locomotor Activity of Mice Treated with α and β-amyrin from Protium heptaphyllum

2018 ◽  
Vol 13 (8) ◽  
pp. 1934578X1801300
Author(s):  
Gislei F. Aragão ◽  
Manoel O. de Moraes Filho ◽  
Paulo N. Bandeira ◽  
Antônio P. Frota Junior ◽  
Yasmin Ingrid S. Oliveira de ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Locomotor Activity ◽  
Open Field ◽  
Field Test ◽  
High Performance ◽  
Open Field Test ◽  
Inhibitory Effect ◽  
Pharmacological Agents ◽  
Tissue Homogenates ◽  
The Central Nervous System

A triterpenic mixture of α and β-amyrin (AMY) extracted from Protium heptaphyllum has demonstrated several pharmacological effects, including activity in the central nervous system. The aim of this study was to evaluate the effect of AMY administration on locomotor activity of mice by the open field test using some monoaminergic agonists and antagonists and the cerebral cortex levels of monoamines and their major metabolites by high-performance liquid chromatography. Mice were treated acutely with AMY at doses of 1, 2.5 and 5 mg/kg given intraperitoneally and with the pharmacological agents and placed in open field test, then the animals were sacrificed and the cerebral cortex extracted, and monoamines were assayed in tissue homogenates. AMY at 1, 2.5 and 5 mg/kg decreased locomotor activity of animals by 25, 31 and 39%, respectively in the open field test. Ondasentron, doxazosin, oxymetazoline and clonidine did not reverse the inhibitory effect of 5 mg/kg AMY. Venlafaxine and yohimbine reversed the inhibitory effect of 5 mg AMY. In the cortex, the 5-HT and 5-HIAA were significantly reduced by the administration of AMY. NE and HVA were also reduced with 2.5 and 5 mg/kg AMY, while Dopamine and DOPAC were not increased with AMY. In conclusion, AMY decreased locomotor activity of animals accompanied by a decrease in 5-HT and NE levels in the cerebral cortex, this locomotor effect is reversed by drug that blocker the α-2-adrenoreceptor.

The effects of low-level lead exposure in developing rats: changes in circadian locomotor activity and hippocampal noradrenaline turnover

1984 ◽  
Vol 62 (4) ◽  
pp. 430-435 ◽  
Author(s):  
M. F. Collins ◽  
P. D. Hrdina ◽  
E. Whittle ◽  
R. L. Singhal
Keyword(s):  
Cerebral Cortex ◽  
Locomotor Activity ◽  
Lead Exposure ◽  
Turnover Rate ◽  
Regional Distribution ◽  
Spontaneous Locomotor Activity ◽  
Noradrenaline Turnover ◽  
Noradrenaline Content ◽  
Noradrenergic Function ◽  
Noradrenaline Levels

The circadian spontaneous locomotor activity of rats exposed to 0.1 mg lead/kg, po from 3 days until 4 and 6 weeks of age was similar to that of controls. However, hyperactivity during initial hours of recording was observed in rats that were treated with lead (Pb) until 8 weeks of age. When treatment was discontinued for 2 weeks, previously Pb-exposed rats had a tendency to be hypoactive. The elevated locomotor activity in 8-week-old lead-treated rats was not accompanied by any significant changes of noradrenaline levels in the cerebral cortex or hippocampus. Alterations in noradrenaline content of the hippocampus were, however, observed in rats that had been treated with Pb for 4 and 6 weeks. The turnover rate of noradrenaline in the hippocampus was also found to be significantly reduced following treatment for 6 weeks. Regional distribution of Pb in the brains of lead-exposed rats showed a large accumulation of the metal in the hippocampus. The alterations of the noradrenergic function in the hippocampus may be associated with the preferential storage of lead in this region.

No changes in behaviour, nigro-striatal system neurochemistry or neuronal cell death following toxic multiple oral paraquat administration to rats

1996 ◽  
Vol 15 (7) ◽  
pp. 583-591 ◽  
Author(s):  
PS Widdowson ◽  
MJ Farnworth ◽  
R. Upton ◽  
MG Simpson
Keyword(s):  
Cerebral Cortex ◽  
Locomotor Activity ◽  
Rat Brain ◽  
Grip Strength ◽  
Cell Damage ◽  
Benzodiazepine Receptors ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Brain Regions ◽  
Nigrostriatal System

We have examined whether the widely used herbicide, paraquat (1,1'-dimethyl-4,4'dipyridylium) may accumu late in rat brain following multiple oral dosing (5 mg paraquat ion/kg/day) for 14 days and whether this dosing regime may produce signs of neurotoxicity. This dosing regime may determine whether low dose exposure to mammals may be neurotoxic. Using [14C]paraquat to measure tissue and plasma paraquat concentrations, we observed significantly higher plasma and tissue paraquat concentrations in brain, liver, lungs and kidneys of rats which received multiple doses for 14 days, as compared to paraquat concentrations in tissues of rats which received only a single paraquat dose. Brain paraquat concentrations measured 24 h after dosing were tenfold higher in rats receiving 14 daily oral doses of paraquat, as compared to concentrations follow ing a single oral dose. A neuropathological study of the rat brain yielded no evidence that multiple paraquat dosing resulted in neuronal cell damage. Particular attention was paid to the nigrostriatal system. The paraquat treated rats gained approximately 10% less body weight over the 15 day experimental period as compared with controls demon strating that the dose of paraquat was toxic to the animals. Measurements of locomotor activity using open field tests or activity monitors did not reveal any statistically significant differences between control animals and those receiving paraquat. Fore- and hind-limb grip strength were not significantly different between the paraquat treated and control rats at any time point during the dosing regime, nor was there any evidence for locomotor co ordination deficits in any of the animals receiving paraquat. Densities of dopamine D1 and D2, NMDA, muscarinic and benzodiazepine receptors in the cerebral cortex and striatum were not significantly different between controls and rats which had received multiple paraquat doses. Concentrations of catecholamine neurotransmitters in the striatum, hypothalamus and frontal cerebral cortex were also measured to examine whether there was evidence for catecholamine depletion in these brain regions. We did not observe any significant reductions in dopamine, noradrenaline or DOPAC concentrations in any brain region of paraquat treated rats as compared with controls. On the contrary, dopamine concentrations in the striatim were significantly elevated in paraquat treated animals following a 15 day paraquat dosing regime. We attribute these changes in catecholamine concentrations to the general toxicity of paraquat which produces a stress response. In conclusion, we could not find any evidence that multiple paraquat dosing can lead to changes in locomotor activity or grip strength. In addition, the absence of neuropathology or changes in neurochemistry in the nigrostriatal tract demonstrates that paraquat does not behave like MPP+(N-methyl-4-phenylpyridinium), the neurotoxic metabolite of MPTP

scholarly journals Effects of sub-chronic amylin receptor activation on alcohol-induced locomotor stimulation and monoamine levels in mice

2020 ◽  
Vol 237 (11) ◽  
pp. 3249-3257 ◽  
Author(s):  
Aimilia Lydia Kalafateli ◽  
Cajsa Aranäs ◽  
Elisabet Jerlhag
Keyword(s):  
Locomotor Activity ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Receptor Activation ◽  
Dopamine Turnover ◽  
Protein Levels ◽  
Locomotor Stimulation ◽  
Term Administration ◽  
Alcohol Response ◽  
Receptor Activity Modifying Proteins

Abstract Rationale Amylin receptors consist of the calcitonin receptor (CTR) and one of three receptor activity-modifying proteins (RAMPs). The identification of amylin receptors in areas processing reward, namely laterodorsal tegmental area (LDTg), ventral tegmental area (VTA), and nucleus accumbens (NAc), has attributed them a role as reward regulators. Indeed, acute activation of amylin receptors by the amylin receptor agonist salmon calcitonin (sCT) attenuates alcohol-induced behaviours in rodents. Objectives The effects of long-term administration of sCT on alcohol-related behaviours and the molecular mechanisms underlying these processes are not yet elucidated. To fill this knowledge gap, we investigated the effects of sub-chronic sCT treatment on the locomotor stimulatory responses to alcohol in mice and the molecular pathways involved. Methods We assessed the behavioural effects of sub-chronic sCT treatment by means of locomotor activity experiments in mice. We used western blot to identify changes of the CTR levels and ex vivo biochemical analysis to detect changes in monoamines and their metabolites. Results After discontinuation for 5 days of sCT treatment, alcohol did not induce locomotor stimulation in mice pre-treated with sCT when compared with vehicle, without altering secondary behavioural parameters of the locomotor activity experiment or the protein levels of the CTR in reward-related areas in the same set of animals. Moreover, repeated sCT treatment altered monoaminergic neurotransmission in various brain areas, including increased serotonin and decreased dopamine turnover in the VTA. Lastly, we identified a differential effect of repeated sCT and acute alcohol administration on alcohol-induced locomotion in mice, where sCT initially attenuated and later increased this alcohol response. It was further found that this treatment combination did not affect secondary behavioural parameters measured in this locomotor activity experiments. Conclusions These data suggest that sub-chronic sCT treatment differentially alters the ability of alcohol to cause locomotor stimulation, possibly through molecular mechanisms involving various neurotransmitter systems and not the CTR levels per se.

scholarly journals Effects of 3-O-Methyldopa, L-3,4-Dihydroxyphenylalanine Metabolite, on Locomotor Activity and Dopamine Turnover in Rats

2012 ◽  
Vol 35 (8) ◽  
pp. 1244-1248 ◽  
Author(s):  
Yoritaka Onzawa ◽  
Yasuhiro Kimura ◽  
Kengo Uzuhashi ◽  
Megumi Shirasuna ◽  
Tasuku Hirosawa ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Dopamine Turnover

Hyperlocomotion during Recovery from Isoflurane Anesthesia Is Associated with Increased Dopamine Turnover in the Nucleus Accumbens and Striatum in Mice

1997 ◽  
Vol 86 (2) ◽  
pp. 464-475 ◽  
Author(s):  
Masahiro Irifune ◽  
Tomoaki Sato ◽  
Takashige Nishikawa ◽  
Takashi Masuyama ◽  
Masahiro Nomoto ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Nucleus Accumbens ◽  
High Performance ◽  
Gas Flow ◽  
Brain Regions ◽  
Dopamine Neurons ◽  
Dopamine Turnover

Background It was recently reported that isoflurane increases dopamine release in the striatum in rats both in vivo and in vitro, and that isoflurane inhibits uptake of dopamine in the rat brain synaptosomes. However, the functional role of these effects of isoflurane on dopamine neurons is uncertain. Dopaminergic mechanisms within the nucleus accumbens and striatum play an important role in the control of locomotor activity, and a change in dopamine turnover depends essentially on a change in impulse flow in the dopamine neurons. In this study, the effects of isoflurane on locomotor activity and on dopamine turnover were investigated in discrete brain regions in mice. Methods Mice were placed in individual airtight clear plastic chambers and spontaneously breathed isoflurane in 25% oxygen and 75% nitrogen (fresh gas flow, 4 l/min). Locomotor activity was measured with an Animex activity meter. Animals were decapitated after treatments with or without isoflurane, and the concentrations of monoamines and their metabolites in different brain areas were measured by high-performance liquid chromatography. Results During the 10 min after the cessation of the 20-min exposure to isoflurane, there was a significant increase in locomotor activity in animals breathing 1.5% isoflurane but not 0.7% isoflurane. This increase in locomotor activity produced by 1.5% isoflurane was abolished by a low dose of haloperidol (0.1 mg/kg), a dopamine receptor antagonist. Regional brain monoamine assays revealed that 1.5% isoflurane significantly increased the 3,4-dihydroxyphenylacetic acid:dopamine ratio (one indicator of transmitter turnover) in the nucleus accumbens and striatum, but a concentration of 0.7% did not. This significant increase in dopamine turnover in these regions continued during 20 min after the cessation of the administration of 1.5% isoflurane. Conclusions These results suggest that isoflurane-induced hyperlocomotion during emergence may be associated with increased dopamine turnover in the nucleus accumbens and striatum.

scholarly journals THE STATE OF THE DOPAMINERGIC SYSTEM OF THE RATS’ BRAIN IN THE MORPHINE-ALCOHOLIC POST-INTOXICATION SYNDROME

2021 ◽  
Vol 19 (3) ◽  
pp. 311-317
Author(s):  
I. M. Vialichko ◽  
◽  
S. V. Lelevich ◽  
Keyword(s):  
Cerebral Cortex ◽  
Dopaminergic System ◽  
Alcohol Intoxication ◽  
Hplc Method ◽  
Male Rats ◽  
Dopamine Turnover ◽  
Psychoactive Substances ◽  
Combined Administration ◽  
The Brain

Background. Opioid addiction, which has arisen against the background of previous alcoholism (or vice versa), is an urgent problem in clinical practice. The change in dopaminergic neuromediation after the withdrawal of the combined effect of ethanol and morphine is currently not clear what was the goal for our study. Purpose. Study of metabolites of the dopaminergic system in the cerebral cortex, striatum and midbrain of rats after different periods of withdrawal of 5-day morphine-alcohol intoxication. Material and methods. The experiments were carried out on 43 white outbred male rats. Using the HPLC method, the levels of metabolites of the dopaminergic system were determined after the withdrawal of the combined administration of morphine and ethanol. Results and conclusions. The severity of changes in metabolites of the dopaminergic system during morphinealcohol withdrawal is determined by the duration and region of the brain. One day after the withdrawal of both psychoactive substances in the striatum and cerebral cortex, a decrease in the concentration of dopamine was observed. In the long-term periods of abolition of intoxication with morphine and ethanol (3, 7 days), the processes of acceleration of dopamine turnover in the midbrain and a decrease in the concentration of the neurotransmitter in the striatum were revealed.

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