title: The metabotropic glutamate receptor 5 role on motor behavior involves specific neural substrates.
abstract: BACKGROUND
  The metabotropic glutamate receptor 5 (mGluR5) is involved in various brain functions, including memory, cognition and motor behavior. Regarding locomotor activity, we and others have demonstrated that pharmacological antagonism of mGluR5 promotes hyperkinesia in mice. Moreover, increased locomotor activity can also be observed in mice following the genetic deletion of mGluR5. However, it is still unclear which specific brain substrates contribute to mGluR5-mediated regulation of motor function.
  
  
  RESULTS
  Thus, to better understand the role of mGluR5 in motor control and to determine which neural substrates are involved in this regulation we performed stereotactic microinfusions of the mGluR5 antagonist, MPEP, into specific brain regions and submitted mice to the open field and rotarod apparatus. Our findings indicate that mGluR5 blockage elicits distinct outcomes in terms of locomotor activity and motor coordination depending on the brain region injected with mGluR5 antagonist. MPEP injection into either the dorsal striatum or dorsal hippocampus resulted in increased locomotor activity, whereas MPEP injection into either the ventral striatum or motor cortex resulted in hypokinesia. Moreover, MPEP injected into the olfactory bulb increased the distance mice traveled in the center of the open field arena. With respect to motor coordination on the rotarod, injection of MPEP into the motor cortex and olfactory bulb elicited decreased latency to fall.
  
  
  CONCLUSIONS
  Taken together, our data suggest that not only primarily motor neural substrates, but also limbic and sensory structures are involved in mGluR5-mediated motor behavior.
authors.affiliation: Departamento de Bioquimica e Imunologia, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil. pandoraufmg@gmail.com.
authors.forename: Isabella M
authors.initials: IM
authors.lastname: Guimaraes
authors.affiliation: Departamento de Bioquimica e Imunologia, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil. toniana_gc@hotmail.com.
authors.forename: Toniana G
authors.initials: TG
authors.lastname: Carvalho
authors.affiliation: J. Allyn Taylor Centre for Cell Biology, Robarts Research Institute, University of Western Ontario, London, Ontario, N6A 5 K8, Canada. ferguson@robarts.ca.
authors.forename: Stephen Sg
authors.initials: SS
authors.lastname: Ferguson
authors.affiliation: Nucleo de Neurociencias, Departamento de Fisiologia e Biofisica, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil. graceschenatto@gmail.com.
authors.forename: Grace S
authors.initials: GS
authors.lastname: Pereira
authors.affiliation: Departamento de Bioquimica e Imunologia, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil. fmribeiro@icb.ufmg.br.
authors.forename: Fabiola M
authors.initials: FM
authors.lastname: Ribeiro
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D009043:Motor Activity / Q000187:drug effects; D009044:Motor Cortex / Q000187:drug effects / Q000378:metabolism; D009434:Neural Pathways / Q000187:drug effects / Q000378:metabolism; D009830:Olfactory Bulb / Q000187:drug effects / Q000378:metabolism; D010296:Parietal Lobe / Q000187:drug effects / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D064529:Receptor, Metabotropic Glutamate 5 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D045442:Rotarod Performance Test
chemical_list: D011725:Pyridines; D064529:Receptor, Metabotropic Glutamate 5; C121465:6-methyl-2-(phenylethynyl)pyridine