title: Place field stability requires the metabotropic glutamate receptor, mGlu5.
abstract: The metabotropic glutamate (mGlu) receptors are critically involved in enabling the persistency of forms of synaptic plasticity that are believed to underlie hippocampus-dependent memory. These receptors and in particular, mGlu5, are also required for hippocampus-dependent learning and memory. In the hippocampus, synaptic plasticity is one of the mechanisms by which spatial information may be represented. Another mechanism involves increased firing of place cells. Place cells increase their firing activity when an animal is in a specific spatial location. Inhibition of factors that are essential for synaptic plasticity, such as N-methyl-d-aspartate receptors or protein synthesis, also impair place cell activity. This raises the question as to whether mGlu receptors, that are so important for synaptic plasticity and spatial memory, are also important for place cell encoding. We examined location-dependent place cell firing i.e. place fields. We observed that antagonism of mGlu5, using 2-methyl-6-(phenylethynyl) pyridine (MPEP) had no effect on place field profiles in a familiar environment. However, in a novel environment mGlu5-antagonism affected long-term place field stability, reduced place cell firing and spatial information. These data strongly suggest a role for mGlu5 in the mechanisms underlying informational content and long-term stability of place fields, and add to evidence supporting the importance of these receptors for hippocampal function.
authors.affiliation: Department of Neurophysiology, Medical Faculty; International Graduate School for Neuroscience, Ruhr University Bochum, Germany.
authors.forename: Sijie
authors.initials: S
authors.lastname: Zhang
authors.forename: Denise
authors.initials: D
authors.lastname: Manahan-Vaughan
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D056547:CA1 Region, Hippocampal / Q000187:drug effects / Q000502:physiology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D008297:Male; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009483:Neuropsychological Tests; D011725:Pyridines / Q000494:pharmacology; D017208:Rats, Wistar; D064529:Receptor, Metabotropic Glutamate 5 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D021641:Recognition, Psychology / Q000187:drug effects / Q000502:physiology; D013028:Space Perception / Q000187:drug effects / Q000502:physiology*
chemical_list: D018691:Excitatory Amino Acid Antagonists; C578937:Grm5 protein, rat; D011725:Pyridines; D064529:Receptor, Metabotropic Glutamate 5; C121465:6-methyl-2-(phenylethynyl)pyridine
keywords: mGlu5; place fields; rat