Excitability tuning of axons in the central nervous system.
The axon is a long neuronal process that originates from the soma and extends towards the presynaptic terminals. The pioneering studies on the squid giant axon or the spinal cord motoneuron established that the axon conducts action potentials faithfully to the presynaptic terminals with self-regenerative processes of membrane excitation. Recent studies challenged the notion that the fundamental understandings obtained from the study of squid giant axons are readily applicable to the axons in the mammalian central nervous system (CNS). These studies revealed that the functional and structural properties of the CNS axons are much more variable than previously thought. In this review article, we summarize the recent understandings of axon physiology in the mammalian CNS due to progress in the subcellular recording techniques which allow direct recordings from the axonal membranes, with emphasis on the hippocampal mossy fibers as a representative en passant axons typical for cortical axons.
Department of Neurobiology, Hokkaido University Graduate School of Medicine, N15 W7 Kita-ku, Sapporo, 060-8638, Japan.
Shunsuke
S
Ohura
Department of Neurobiology, Hokkaido University Graduate School of Medicine, N15 W7 Kita-ku, Sapporo, 060-8638, Japan. kamiya@med.hokudai.ac.jp.
Haruyuki
H
Kamiya
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001369:Axons / Q000502:physiology* / Q000648:ultrastructure; D002490:Central Nervous System / Q000033:anatomy & histology / Q000502:physiology*; D019599:Mossy Fibers, Hippocampal / Q000033:anatomy & histology / Q000502:physiology; D015221:Potassium Channels / Q000502:physiology; D015222:Sodium Channels / Q000502:physiology
D015221:Potassium Channels; D015222:Sodium Channels
Axon; En passant axons; Initial segment; Mossy fiber; Propagation failure; Subcellular recording