Two types of interneurons in the mouse lateral geniculate nucleus are characterized by different h-current density.
Although hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels and the corresponding h-current (Ih) have been shown to fundamentally shape the activity pattern in the thalamocortical network, little is known about their function in local circuit GABAergic interneurons (IN) of the dorsal part of the lateral geniculate nucleus (dLGN). By combining electrophysiological, molecular biological, immunohistochemical and cluster analysis, we characterized the properties of Ih and the expression profile of HCN channels in IN. Passive and active electrophysiological properties of IN differed. Two subclasses of IN were resolved by unsupervised cluster analysis. Small cells were characterized by depolarized resting membrane potentials (RMP), stronger anomalous rectification, higher firing frequency of faster action potentials (APs), appearance of rebound bursting, and higher Ih current density compared to the large IN. The depolarization exerted by sustained HCN channel activity facilitated neuronal firing. In addition to cyclic nucleotides, Ih in IN was modulated by PIP2 probably based on the abundant expression of the HCN3 isoform. Furthermore, only IN with larger cell diameters expressed neuronal nitric oxide synthase (nNOS). It is discussed that Ih in IN is modulated by neurotransmitters present in the thalamus and that the specific properties of Ih in these cells closely reflect their modulatory options.
Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany.
Michael
M
Leist
Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany.|Laboratory of Sleep-Wakefulness Cycle Studies, Faculty of Arts and Science, Ilia State University, Kakutsa Cholokashvili Ave 3/5, Tbilisi 0162, Georgia.
Maia
M
Datunashvilli
Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany.
Tatyana
T
Kanyshkova
Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany.
Mehrnoush
M
Zobeiri
Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany.
Ania
A
Aissaoui
Institut für Physiologie I - Neuropathophysiologie, Albert-Schweitzer Campus 1, 48149 Münster, Germany.
Manuela
M
Cerina
Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
Maria Novella
MN
Romanelli
Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany.
Hans-Christian
HC
Pape
Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany.
Thomas
T
Budde
D000200:Action Potentials; D000818:Animals; D059330:GABAergic Neurons / Q000145:classification* / Q000502:physiology*; D005829:Geniculate Bodies / Q000166:cytology*; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels / Q000032:analysis*; D007395:Interneurons / Q000145:classification* / Q000502:physiology*; D051379:Mice
D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels