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.

scholarly journals Spontaneous Locomotor Activity and Life Span

Gerontology ◽  
1985 ◽  
Vol 31 (5) ◽  
pp. 335-337 ◽  
Author(s):  
F.A. Lints ◽  
E. Le Bourg ◽  
C.V. Lints
Keyword(s):  
Locomotor Activity ◽  
Life Span ◽  
Spontaneous 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.

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