Group I mGlu receptors regulate the expression of the neuronal calcium sensor protein VILIP-1 in vitro and in vivo: implications for mGlu receptor-dependent hippocampal plasticity?
Metabotropic glutamate (mGlu) receptors are involved in several forms of synaptic plasticity in the rat hippocampus. Agonists which activate group I mGlu receptors induce slow-onset potentiation without prior tetanization in the hippocampal area CA1. Activation of group I mGlu receptors induces protein synthesis which may contribute to mGlu receptor-dependent forms of long-term plasticity. Calcium-binding proteins are widely considered to comprise key elements for synaptic plasticity. Therefore, we investigated whether the calcium sensor protein VILIP-1 is associated with group I mGlu receptor-mediated plasticity in the dentate gyrus (DG) in vivo.Application of either the group I and II mGlu agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylate (ACPD) or the selective group I agonist (R,S)-3,5-dihydroxyphenylglycine (DHPG) resulted in slow-onset potentiation in the DG of adult rats. In hippocampal cell cultures both agonists elicited an enhanced expression of VILIP-1. In situ hybridization revealed strong hippocampal expression of VILIP-1 and intracerebral application of DHPG to adult rats significantly enhanced hippocampal VILIP-1 expression. The DHPG effects in both, hippocampal cultures and in vivo, were prevented by the group I mGlu receptor antagonist 4-Carboxyphenylglycine (4CPG). Calcium sensor proteins thus appear to be regulated by mGlu receptors in an activity-dependent manner. A specific role for group I mGlu receptors is evident. Furthermore, the sensor proteins may function as molecular switches for the long-term regulation of synaptic plasticity.
Braunewell
K-H
KH
Signal Transduction Research Group, Neuroscience Research Center of the Charite, Humboldt University, Tucholskystr 2, D-10117, Berlin, Germany. karl-heinz.braunewell@charite.de
Brackmann
M
M
Manahan-Vaughan
D
D
D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D018891:Dentate Gyrus / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D004148:Dioxolanes / Q000494:pharmacology; D005071:Evoked Potentials / Q000187:drug effects; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D051596:Neurocalcin; D009473:Neuronal Plasticity; D011687:Purines / Q000494:pharmacology; D017966:Pyramidal Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D044169:Receptors, Calcium-Sensing; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012118:Resorcinols / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects; D015854:Up-Regulation
D001565:Benzoates; D002135:Calcium-Binding Proteins; D004148:Dioxolanes; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D009419:Nerve Tissue Proteins; D051596:Neurocalcin; D011687:Purines; D012333:RNA, Messenger; D044169:Receptors, Calcium-Sensing; D018094:Receptors, Metabotropic Glutamate; D012118:Resorcinols; C496690:Vsnl1 protein, rat; C104068:4-(2-amino-6-chloro-9H-purin-9-yl)-1,3-dioxolane-2-methanol; C079215:3,5-dihydroxyphenylglycine; C079693:4-carboxyphenylglycine; D005998:Glycine