Activation of M2 muscarinic receptors leads to sustained suppression of hippocampal transmission in the medial prefrontal cortex.
Cholinergic innervation of the prefrontal cortex is critically involved in arousal, learning and memory. Dysfunction of muscarinic acetylcholine receptors and their downstream signalling pathways has been identified in mental retardation. To assess the role played by the muscarinic receptors at the hippocampal-frontal cortex synapses, an important relay in information storage, we used a newly developed frontal slice preparation in which hippocampal afferent fibres are preserved. Transient activation of muscarinic receptors by carbachol results in a long-lasting depression of synaptic efficacy at the hippocampal but not cortical pathways or local circuitry. On the basis of a combination of electrophysiological, pharmacological and anatomical results, this input-specific muscarinic modulation can be partially attributed to the M2 subtype of muscarinic receptors, possibly through a combination of pre- and postsynaptic mechanisms.
Wang
Lang
L
Department of Neuroscience, University of Minnesota, 321 Church St. SE, Minneapolis, MN 55455, USA.
Yuan
Li-Lian
LL
D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D002478:Cells, Cultured; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D017397:Prefrontal Cortex / Q000187:drug effects / Q000502:physiology*; D043585:Receptor, Muscarinic M2 / Q000819:agonists / Q000378:metabolism*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*
D043585:Receptor, Muscarinic M2; D002217:Carbachol