title: Development of Electrophysiological Properties of Nucleus Gigantocellularis Neurons Correlated with Increased CNS Arousal.
abstract: Many types of data have suggested that neurons in the nucleus gigantocellularis (NGC) in the medullary reticular formation are critically important for CNS arousal and behavioral responsiveness. To extend this topic to a developmental framework, whole-cell patch-recorded characteristics of NGC neurons in brainstem slices and measures of arousal-dependent locomotion of postnatal day 3 (P3) to P6 mouse pups were measured and compared. These neuronal characteristics developed in an orderly, statistically significant monotonic manner over the course of P3-P6: (1) proportion of neurons capable of firing action potential (AP) trains, (2) AP amplitude, (3) AP threshold, (4) amplitude of inward and outward currents, (5) amplitude of negative peak currents, and (6) steady state currents (in I-V plot). These measurements reflect the maturation of sodium and certain potassium channels. Similarly, all measures of locomotion, latency to first movement, total locomotion duration, net locomotion distance, and total quiescence time also developed monotonically over P3-P6. Most importantly, electrophysiological and behavioral measures were significantly correlated. Interestingly, the behavioral measures were not correlated with frequency of excitatory postsynaptic currents or the proportion of neurons showing these currents, responses to a battery of neurotransmitter agents, or rapid activating potassium currents (including IA). Considering the results here in the context of a large body of literature on NGC, we hypothesize that the developmental increase in NGC neuronal excitability participates in causing the increased behavioral responsivity during the postnatal period from P3 to P6.
authors: Laboratory of Neurobiology and Behavior, The Rockefeller University, New York, N.Y., USA.
authors: Xu
authors: X
authors: Liu
authors: Donald W
authors: DW
authors: Pfaff
authors: Diany P
authors: DP
authors: Calderon
authors: Inna
authors: I
authors: Tabansky
authors: Xin
authors: X
authors: Wang
authors: Yun
authors: Y
authors: Wang
authors: Lee-Ming
authors: LM
authors: Kow
mesh_terms: D000818:Animals; D001143:Arousal / Q000502:physiology; D001522:Behavior, Animal / Q000502:physiology*; D002490:Central Nervous System / Q000378:metabolism*; D055724:Electrophysiological Phenomena; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods; D015221:Potassium Channels / Q000378:metabolism*
chemical_list: D015221:Potassium Channels