Muscarinic cholinergic modulation of synaptic transmission and plasticity in rat hippocampus following chronic lead exposure
| Autor: | Di-Yun Ruan, Yun-Yun Luo, Le Luo, Ming Wang, Mingliang Tang, Hui-Li Wang, Da-Miao Zhu |
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| Rok vydání: | 2008 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Carbachol viruses Long-Term Potentiation Hippocampus Muscarinic Antagonists Diamines In Vitro Techniques Muscarinic Agonists Neurotransmission Synaptic Transmission chemistry.chemical_compound Memory Internal medicine Muscarinic acetylcholine receptor Methoctramine medicine Animals Learning Rats Wistar Pharmacology Neuronal Plasticity Excitatory Postsynaptic Potentials virus diseases Long-term potentiation Pirenzepine General Medicine biochemical phenomena metabolism and nutrition Receptors Muscarinic Rats respiratory tract diseases Endocrinology Lead chemistry Excitatory postsynaptic potential Environmental Pollutants Female medicine.drug |
| Zdroj: | Naunyn-Schmiedeberg's Archives of Pharmacology. 379:37-45 |
| ISSN: | 1432-1912 0028-1298 |
| DOI: | 10.1007/s00210-008-0344-1 |
| Popis: | The cholinergic system is believed to be associated with learning and memory functions. Lead (Pb2+) is a well-known neurotoxic metal that causes irreversible damage to the central nervous system (CNS). To investigate whether Pb2+ interferes with cholinergic modulation, we examined the effects of carbachol (CCh), a muscarinic cholinergic agonist, on synaptic transmission and plasticity in the CA1 area of the hippocampus of developmentally Pb2+-exposed rats. The results showed that: (1) In both control and Pb2+-exposed rats, 0.1 microM CCh significantly enhanced tetanus-induced long-term potentiation (LTP), while 5 microM CCh induced a reversible depression of field excitatory postsynaptic potentials (fEPSPs). However, both the enhancement of LTP and depression of fEPSPs were significantly smaller in Pb2+-exposed rats than in controls, suggesting that the extent of the effect of CCh on the cholinergic system was depressed by Pb2+. (2) In Pb2+-exposed rats, the enhancement of LTP induced by 0.1 microM CCh was attenuated by pirenzepine, a M1AChR antagonist, but was not affected by methoctramine tetrahydrochloride (M-105), a M2/4AChR antagonist. The depression of fEPSPs induced by 5 microM CCh was reduced by either pirenzepine or M-105. (3) Furthermore, paired-pulse facilitation (PPF) was not affected by 0.1 microM CCh in control and Pb2+-exposed rats but was increased by 5 microM CCh in either group; the increase in PPF was less pronounced in Pb2+-treated when compared to control rats. These results suggested that cholinergic modulation could be impaired by Pb2+, and this kind of impairment might occur via different mAChR subtypes. Our study delineated the effects of Pb2+ on muscarinic modulation, and this might be one of the underlying mechanisms by which Pb2+ impairs learning and memory. |
| Databáze: | OpenAIRE |
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