Metabotropic Glutamate Agonist-Induced Rotation: A Pharmacological, FOS Immunohistochemical, and [14C]-2-Deoxyglucose Autoradiographic Study

摘要: Metabotropic glutamate receptors (mGluRs) are a major class of excitatory amino acid receptors. Eight mGluR subtypes, coupled to variety effector systems, have been cloned. These classified into three groups based on sequence homology, and pharmacological profile. Group I mGluRs increase phosphoinositide turnover, whereas II III negatively adenylyl cyclase. The striatum possesses high density binding sites, several mRNAs proteins expressed by striatal neurons. In rats, unilateral injection the nonsubtype selective agonist 1-aminocyclopentane-1S,3R-dicarboxylic (1S,3R-ACPD) results in contralateral rotation with delayed onset, thought be secondary an dopamine release. We sought determine subtype(s) involved, modulation other basal ganglia neurotransmitter functional anatomy underlying rotational behavior. group 3,5-dihydroxyphenylglycine (DHPG) induced dose-dependent manner, agonists were ineffective. Rotation DHPG or 1S,3R-ACPD was attenuated antagonists, but not antagonists. This suggests that is mediated mGluRs. pretreatment antagonists at muscarinic cholinergic, adenosine A2, D2, D1 Examination FOS-like immunoreactivity after administration increased activity striatopallidal pathway. However, [14C]-2-deoxyglucose uptake studies indicate nuclei (indirect) pathway, particularly subthalamic nucleus, only activation.