title: Statistical models suggest presence of two distinct subpopulations of miniature EPSCs in fast-spiking interneurons of rat prefrontal cortex.
abstract: Properties of excitatory synaptic responses in fast-spiking interneurons (FSIs) and pyramidal neurons (PNs) are different; however, the mechanisms and determinants of this diversity have not been fully investigated. In the present study, voltage-clamp recording of miniature excitatory post-synaptic currents (mEPSCs) was performed of layer 2-3 FSIs and PNs in the medial prefrontal cortex of rats aged 19-22days. The average mEPSCs in the FSIs exhibited amplitudes that were two times larger than those of the PNs and with much faster rise and decay. The mEPSC amplitude distributions in both cell types were asymmetric and in FSIs, the distributions were more skewed and had two-times larger coefficients of variation than in the PNs. In PNs but not in FSIs, the amplitude distributions were fitted well by different skewed unimodal functions that have been used previously for this purpose. In the FSIs, the distributions were well approximated only by a sum of two such functions, suggesting the presence of at least two subpopulations of events with different modal amplitudes. According to our estimates, two-thirds of the mEPSCs in FSIs belong to the high-amplitude subpopulation, and the modal amplitude in this subpopulation is approximately two times larger than that in the low-amplitude subpopulation. Using different statistical models, varying binning size, and data subsets, we confirmed the robustness and consistency of these findings.
authors.affiliation: Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (IEPhB), Toreza pr., 44, Saint Petersburg 194223, Russia.
authors.forename: S L
authors.initials: SL
authors.lastname: Malkin
authors.affiliation: Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (IEPhB), Toreza pr., 44, Saint Petersburg 194223, Russia.
authors.forename: K K
authors.initials: KK
authors.lastname: Kim
authors.affiliation: Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (IEPhB), Toreza pr., 44, Saint Petersburg 194223, Russia.
authors.forename: D B
authors.initials: DB
authors.lastname: Tikhonov
authors.affiliation: Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (IEPhB), Toreza pr., 44, Saint Petersburg 194223, Russia; St Petersburg State University, Universitetskaya nab., 7-9, Saint Petersburg 199034, Russia.
authors.forename: L G
authors.initials: LG
authors.lastname: Magazanik
authors.affiliation: Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (IEPhB), Toreza pr., 44, Saint Petersburg 194223, Russia. Electronic address: aleksey_zaitsev@mail.ru.
authors.forename: A V
authors.initials: AV
authors.lastname: Zaitsev
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D055592:Biophysical Phenomena / Q000187:drug effects / Q000502:physiology; D001703:Biophysics; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D007395:Interneurons / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D008297:Male; D015233:Models, Statistical; D018408:Patch-Clamp Techniques; D017397:Prefrontal Cortex / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D026941:Sodium Channel Blockers / Q000494:pharmacology; D018709:Statistics, Nonparametric; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D026941:Sodium Channel Blockers; D013779:Tetrodotoxin
keywords: excitatory postsynaptic current; fast-spiking interneuron; prefrontal cortex; quantal response