The cerebral cortex and locomotor activity in rats.

1952 ◽  
Vol 6 (2) ◽  
pp. 55-70 ◽  
Author(s):  
John P. Zubek ◽  
A. J. De Lorenzo
Keyword(s):  
Cerebral Cortex ◽  
Locomotor Activity

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

Author response for "Microchiropterans have a diminutive cerebral cortex, not an enlarged cerebellum, compared to megachiropterans and other mammals"

2020 ◽  
Author(s):  
Suzana Herculano‐Houzel ◽  
Felipe Barros Cunha ◽  
Jamie L. Reed ◽  
Consolate Kaswera‐Kyamakya ◽  
Emmanuel Gillissen ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Author Response
Sign in / Sign up

Export Citation Format

Share Document