title: Metabotropic glutamate receptors inhibit GABA release in rat histamine neurons.
abstract: The modulation of GABAergic transmission by metabotropic glutamate (mGlu) receptors was examined in histaminergic neurons using a conventional whole-cell patch clamp technique. DHPG, a selective group I mGlu receptor agonist, had no effect on GABAergic inhibitory postsynaptic currents (IPSCs). However, DCG-IV (1μМ) and L-AP4 (1μМ), selective group II or III mGlu receptor agonists, respectively, decreased the amplitude of GABAergic IPSCs and simultaneously increased the paired-pulse ratio. The inhibitory effect of DCG-IV was completely blocked by 200nM LY341495, a group II and III mGlu receptor antagonist, and the inhibitory effect of L-AP4 was completely blocked by 10μМ LY341495. These results suggest that multiple mGlu receptors are involved in regulating the excitability of histaminergic neurons.
authors: Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea; Brain Science & Engineering Institute, Kyungpook National University, Daegu, Republic of Korea. Electronic address: jis7619@mail.knu.ac.kr.
authors: Il-Sung
authors: IS
authors: Jang
mesh_terms: D000818:Animals; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D005260:Female; D018755:GABA Agonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D006632:Histamine / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000187:drug effects; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists*; D017661:Receptors, Presynaptic / Q000187:drug effects; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D018755:GABA Agonists; D018756:GABA Antagonists; D011963:Receptors, GABA-A; D018094:Receptors, Metabotropic Glutamate; D017661:Receptors, Presynaptic; D005680:gamma-Aminobutyric Acid; D006632:Histamine
keywords: GABAergic IPSCs; Metabotropic glutamate receptors; Patch clamp; Sleep-wakefulness; Tuberomammillary nucleus