These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Bidirectional modulation of long-term potentiation by carbachol via M1 and M2 muscarinic receptors in guinea pig hippocampal mossy fiber-CA3 synapses.
    Author: Maeda T, Kaneko S, Satoh M.
    Journal: Brain Res; 1993 Aug 13; 619(1-2):324-30. PubMed ID: 8104089.
    Abstract:
    Participation of muscarinic M1 and M2 receptors in the modulation of long-term potentiation (LTP) was studied in the mossy fiber-CA3 synapse of guinea pig hippocampal slices. The magnitude of tetanus-induced LTP was attenuated in the presence of 0.01-0.1 microM carbachol, at which concentration the pre-tetanus amplitude of field excitatory postsynaptic potential (fEPSP) was not affected. The attenuation of LTP by the low concentration of carbachol was reversed by an M2 muscarinic antagonist, AF-DX 116, but not by an M1 antagonist, pirenzepine. On the contrary, a high concentration (10 microM) of carbachol decreased the pre-tetanic amplitude of fEPSP, however, the magnitude of LTP was significantly larger than that in control slices in which pre-tetanic amplitude of fEPSP was reduced to the level of carbachol-treated slices by reducing the intensity of stimulation or extracellular Ca2+ concentration. The augmentation of LTP by 10 microM carbachol was blocked by pirenzepine but not by AF-DX 116. These results suggest that the synaptic plasticity in the guinea pig hippocampal mossy fiber-CA3 synapse is inhibited and facilitated by muscarinic agonist through muscarinic M2 and M1 receptors to inhibit and facilitate the LTP, respectively.
    [Abstract] [Full Text] [Related] [New Search]