Biomaterial Database

Electrophysiological properties of phrenic motoneurons in adult rats. 1995

F Hayashi, and Y Fukuda

Department of Physiology, School of Medicine, Chiba University, Japan.

Electrophysiological properties of phrenic motoneurons (PMs) were studied by intracellular recordings in anesthetized, paralyzed, and artificially ventilated adult rats. Our results revealed that rat PMs, as compared to cat PMs, had a shorter afterhyperpolarization duration (55 +/- 13 ms; mean +/- SD), a narrower half-width of action potential, a larger membrane input resistance (Rm; 2.0 +/- 0.6 M omega), a smaller rheobase (Irh) and a shorter minimum paired pulse interval to provoke the second spike (1.9 +/- 0.6 ms). These features indicate that the rat PMs possess higher frequency responsiveness than cat PMs. Based on the time of firing onset relative to the onset of whole phrenic nerve activity (relative onset time; ROT) or on the absence of discharge during inspiration, the PMs could be classified into four types: early recruited with ROT < 10.0%; late recruited with 12.5% < ROT < 37.5%; very late recruited with ROT > 45%, and quiescent which was not recruited during normal experimental conditions. A number of differences in the membrane properties such as end-expiratory membrane potential, Rm, and Irh among the four cell types are discussed in relation to the recruitment order. Inhibitory postsynaptic potentials (IPSPs) were present during the late expiratory phase (stage II expiration) in all PMs tested.

UI	MeSH Term	Description	Entries
D007395	Interneurons	Most generally any NEURONS which are not motor or sensory. Interneurons may also refer to neurons whose AXONS remain within a particular brain region in contrast to projection neurons, which have axons projecting to other brain regions.	Intercalated Neurons,Intercalated Neuron,Interneuron,Neuron, Intercalated,Neurons, Intercalated
D008297	Male		Males
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D010791	Phrenic Nerve	The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.	Nerve, Phrenic,Nerves, Phrenic,Phrenic Nerves
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D011999	Recruitment, Neurophysiological	The spread of response if stimulation is prolonged. (Campbell's Psychiatric Dictionary, 8th ed.)	Recruitment, Motor Unit,Motor Unit Recruitment,Neurophysiological Recruitment
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.