title: Single cell analysis of voltage-gated potassium channels that determines neuronal types of rat hypothalamic paraventricular nucleus neurons.
abstract: The hypothalamic paraventricular nucleus (PVN), a site for the integration of both the neuroendocrine and autonomic systems, has heterogeneous cell composition. These neurons are classified into type I and type II neurons based on their electrophysiological properties. In the present study, we investigated the molecular identification of voltage-gated K+ (Kv) channels, which determines a distinctive characteristic of type I PVN neurons, by means of single-cell reverse transcription-polymerase chain reaction (RT-PCR) along with slice patch clamp recordings. In order to determine the mRNA expression profiles, firstly, the PVN neurons of male rats were classified into type I and type II neurons, and then, single-cell RT-PCR and single-cell real-time RT-PCR analysis were performed using the identical cell. The single-cell RT-PCR analysis revealed that Kv1.2, Kv1.3, Kv1.4, Kv4.1, Kv4.2, and Kv4.3 were expressed both in type I and in type II neurons, and several Kv channels were co-expressed in a single PVN neuron. However, we found that the expression densities of Kv4.2 and Kv4.3 were significantly higher in type I neurons than in type II neurons. Taken together, several Kv channels encoding A-type K+ currents are present both in type I and in type II neurons, and among those, Kv4.2 and Kv4.3 are the major Kv subunits responsible for determining the distinct electrophysiological properties. Thus these 2 Kv subunits may play important roles in determining PVN cell types and regulating PVN neuronal excitability. This study further provides key molecular mechanisms for differentiating type I and type II PVN neurons.
authors.affiliation: Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea.
authors.forename: S K
authors.initials: SK
authors.lastname: Lee
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: S Y
authors.initials: SY
authors.lastname: Shin
authors.forename: P D
authors.initials: PD
authors.lastname: Ryu
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000235:genetics; D009474:Neurons / Q000145:classification* / Q000166:cytology / Q000502:physiology*; D009924:Organ Culture Techniques; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology* / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D051672:Shal Potassium Channels / Q000235:genetics / Q000502:physiology*
chemical_list: D051672:Shal Potassium Channels