title: Corticotropin-releasing factor-like peptide modifies the AMPA-, NMDA-dependent and GABAB-ergic properties of synaptic transmissions in vitro.
abstract: The aim of this study was to investigate the neurotrophic effects of the mystixin-7 mini-peptide (MTX, a synthetic corticotrophin-releasing-factor-like peptide-like peptide) using a slice-based system. The technique on-line monitoring of electrophysiological parameters (excitatory glutamatergic AMPAR-, NMDAR-dependent and inhibitory GABAB-ergic postsynaptic mechanisms) in the olfactory cortex slices of the rat brain exposed to varied amounts of MTX was used. MTX in a dose-dependent manner inhibited both the AMPAR- and NMDAR-mediated postsynaptic processes. The peptide caused depression of inhibitory GABAB-ergic processes only at low doses of MTX (10, 25, 50 mg/mL) while at higher doses (100, 250 mg/mL) it enhanced them. These effects of MTX were reversible. AMPA-dependent (but not NMDA-mediated mechanisms) and inhibitory processes were restored after washing. Triple reperfusion of slices with MTX (100 mg/mL) accelerated the inhibitory processes and induced NMDAR desensitization. MTX evoked the long-term depression on θ burst stimulation of the slices. This study did not only lead to the conclusion that the functions of the MTX mini-peptide is not limited to anti-inflammatory effects, but also is included modifications of excitatory glutamatergic AMPAR-, NMDAR-dependent and inhibitory GABAB-ergic postsynaptic mechanisms.
authors.affiliation: I. P. Pavlov Institute of Physiology, Russian Academy of Science, Nab. Makarova 6, Saint-Petersburg 199034, Russia. Electronic address: mok@inbox.ru.
authors.forename: Anatoly A
authors.initials: AA
authors.lastname: Mokrushin
mesh_terms: D000818:Animals; D018683:Excitatory Amino Acid Agents / Q000494:pharmacology*; D019706:Excitatory Postsynaptic Potentials; D059330:GABAergic Neurons / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects; D008297:Male; D009414:Nerve Growth Factors / Q000494:pharmacology; D009833:Olfactory Pathways / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D009842:Oligopeptides / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects*
chemical_list: D018683:Excitatory Amino Acid Agents; D009414:Nerve Growth Factors; D009842:Oligopeptides; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; C110632:mystixin 7
keywords: AMPA-; IPSPs; LTP/LTD; Mystixin-7; NMDA EPSP