title: Development of NMDA-induced theta rhythm in hippocampal formation slices.
abstract: During the past 20 years experimental evidence has accumulated demonstrating that the appearance of theta rhythm requires a certain level of excitation of local neuronal networks. In this study we extended our earlier in vitro observations concerning the involvement of cholinergic and GABAergic neurotransmission in hippocampal theta production. Specifically, we investigated whether the hippocampal neuronal network is capable of generating theta oscillations in the presence of N-methyl-d-aspartic acid (NMDA) in a brain slice preparation. To answer this question, the effect of different concentrations of NMDA (Experiment I) and the effect of interaction between NMDA and GABAA/B agonists and antagonists on field potentials recorded in the CA3c region of hippocampal formation (HPC) slice preparations (Experiment II) was examined. We demonstrated for the first time that apart from the epileptiform activity recorded in almost all series of Experiments I and II, only the perfusion of HPC slices with NMDA in doses of 30 and 50 μM, as well as the perfusion of HPC slices with NMDA and GABAB agonist baclofen (50 μM NMDA+50 μM BACL), resulted in the appearance of individual theta epochs. The best synchronized theta oscillations obtained after administration of 50 μM NMDA+50 μM BACL resembled theta activity induced by a bath perfusion of 50 μM carbachol. In light of the obtained results we conclude that besides the cholinergic and GABAergic input, NMDA glutamatergic drive is also important for the appearance of theta oscillations in HPC in vitro.
authors.affiliation: Department of Neurobiology, Faculty of Biology and Environmental Protection, University of Łódź, Pomorska Street 141/143, 90-236 Łódź, Poland. Electronic address: kazmierskapaulina@gmail.com.
authors.forename: Paulina
authors.initials: P
authors.lastname: Kazmierska
authors.forename: Jan
authors.initials: J
authors.lastname: Konopacki
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D001418:Baclofen / Q000031:analogs & derivatives / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018682:GABA Agents / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology*; D051381:Rats; D013826:Theta Rhythm / Q000187:drug effects*; D013997:Time Factors
chemical_list: D018679:Cholinergic Agonists; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D018682:GABA Agents; D009118:Muscimol; D016202:N-Methylaspartate; D015763:2-Amino-5-phosphonovalerate; D002217:Carbachol; D001418:Baclofen; C057491:2-hydroxysaclofen; D001640:Bicuculline
keywords: 2-HS; 2-hydroxy-saclophen; 6-cyano-7-nitroquinoxaline-2,3-dione; ACSF; AMPA; APV; BACL; BICU; CA; CCH; CNQX; DG; EEG; Epilepsy; FFT; Fast Fourier Transform; GABA; HPC; Hippocampal formation; In vitro; LTP; MRn; MS/DBB; MUSC; N-methyl-d-aspartic acid; NMDA; O-LM; Oriens-Lacunosum Moleculare; PV; SuM; Theta rhythm; artificial cerebrospinal fluid; baclofen; bicuculine; carbachol; cornu ammonis; d,l-2-amino-5-phosphonopentanoic acid; d-(−)-2-amino-5-phosphonopentanoic acid; d-AP5; dentate gyrus; diagonal band of Broca; electroencephalography; hippocampal formation; long-term potentiation; median raphe nuclei; muscimol; parvalbumin; supramammillary body; α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate; γ-aminobutyric acid