title: Modulatory effects of metabotropic glutamate receptors on local cortical circuits.
abstract: Glutamatergic pathways in various thalamic and cortical circuits have been classified into two types: Class 1 and Class 2, where it has been suggested that Class 1 carries the main information for processing, and Class 2 is mainly modulatory. We now extend this to the local circuitry of visual cortex of the mouse by demonstrating the modulatory actions on the Class 1 pathway from layer 4 to layers 2/3 of a Class 2 input from adjacent locations in layers 2/3. We found that this Class 2 input produces a long-lasting hyperpolarization and suppresses the initial responses of input from layer 4 and that this involves the postsynaptic activation of Group II metabotropic glutamate receptors. This modulation also shifts the paired pulse ratio of the layer 4 input from depression to facilitation.
authors.affiliation: Department of Neurobiology, University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: Roberto
authors.initials: R
authors.lastname: De Pasquale
authors.forename: S Murray
authors.initials: SM
authors.lastname: Sherman
mesh_terms: D000818:Animals; D004558:Electric Stimulation / Q000379:methods; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D014793:Visual Cortex / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*
chemical_list: D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D018094:Receptors, Metabotropic Glutamate; C108822:metabotropic glutamate receptor 2