title: Separation of electrophysiologically distinct neuronal populations in the rat hippocampus for neuropharmacological testing under in vivo conditions.
abstract: Microiontophoresis combined with extracellular spike recording is an excellent method for investigating local neuropharmacological effects under in vivo conditions. However, its application has recently become relatively rare in neuroscience research. Now, we aimed to revisit microiontophoresis and demonstrate that it provides valuable data about the pharmacophysiology of neurons and local neuronal networks, in vivo. Extracellular recordings were performed through the central recording channel of multibarrel carbon-fiber microelectrodes in the CA1 pyramidal layer of the hippocampus of anesthetized rats, while N-methyl-D-aspartate (NMDA) was locally administrated by means of microiontophoresis through the surrounding micropipettes of the microelectrode. Various separation procedures were used to distinguish putative pyramidal cells and interneurons. Quality of separation was verified by electrophysiological parameters. After the delivery of NMDA in the vicinity of the examined neurons, firing rate of putative pyramidal cells was increased with a significantly higher grade then that of putative interneurons. The present results in line with previous data indicate that pyramidal cells are more responsive to pharmacological manipulation through NMDA receptors, also confirming the reliability of the separation of different types of neurons in in vivo microiontophoretic experiments.
authors.affiliation: University of Pécs Department of Experimental Zoology and Neurobiology, and Szentágothai Research Center Pécs Hungary.
authors.forename: Z K
authors.initials: ZK
authors.lastname: Bali
authors.affiliation: Kation Scientific, LLC Minneapolis MN USA.
authors.forename: D
authors.initials: D
authors.lastname: Budai
authors.affiliation: University of Pécs Department of Experimental Zoology and Neurobiology, and Szentágothai Research Center Pécs Hungary.
authors.forename: I
authors.initials: I
authors.lastname: Hernádi
mesh_terms: D000200:Action Potentials; D000818:Animals; D002469:Cell Separation / Q000379:methods*; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D007395:Interneurons / Q000187:drug effects* / Q000378:metabolism; D007478:Iontophoresis; D016202:N-Methylaspartate / Q000494:pharmacology*; D017966:Pyramidal Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists* / Q000378:metabolism; D012815:Signal Processing, Computer-Assisted; D012984:Software; D013997:Time Factors
chemical_list: D018690:Excitatory Amino Acid Agonists; D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate
keywords: Extracellular recording; clustering; interneurons; microiontophoresis; pyramidal cells