Biomaterial Database

Postnatal development of voltage-gated K currents on rat sympathetic neurons. 1992

S McFarlane, and E Cooper

Department of Physiology, McGill University, Montreal, Quebec, Canada.

1. We have investigated the developmental expression of three voltage-gated K currents on neonatal rat superior cervical ganglion (SCG) neurons in vivo and in culture: a rapidly inactivating current (IAf), a slowly inactivating current (IAs), and a noninactivating current (IK). 2. On postnatal day 1 neurons (P1), mean peak IAs is 67 +/- 4 (SE) pA/pF, peak IAf is 27 +/- 3 pA/pF, and IK is 14 +/- 3 pA/pF. Over the next wk, there is a switch in the expression of these currents: IAs drops by 40%, whereas IAf increases by greater than 100%; there is no change in IK. On P14 neurons, IAs is 38 +/- 2 pA/pF, IAf is 64 +/- 5 pA/pF, and IK is 12 +/- 1 pA/pF. 3. The change in expression of K currents on SCG neurons over the first 2 postnatal wk is unaffected by preganglionic innervation or by innervation of the targets. 4. To learn more about the factors that affect K current expression on these neurons, we grew SCG neurons in culture without other cell types for various times, and we measured the expression of IAf, IAs, and IK. In culture, the currents remained at their P1 levels for the first 4-7 days. Thereafter, both IAs and IAf decreased to low levels over a period of 2-3 wk. These results suggest that an epigenetic factor(s) is necessary for the expression of IAf and IAf in vivo and that this factor is missing in culture. 5. When IAs and IAf decreased on neurons in culture, we observed a compensatory increase in IK. After 4 wk in culture, IK is fourfold greater than on neurons in vivo. This result suggests that these neurons have intrinsic mechanisms that coordinate the expression of different voltage-gated K currents.

UI	MeSH Term	Description	Entries
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D003714	Denervation	The resection or removal of the nerve to an organ or part.	Laser Neurectomy,Neurectomy,Peripheral Neurectomy,Radiofrequency Neurotomy,Denervations,Laser Neurectomies,Neurectomies,Neurectomies, Laser,Neurectomies, Peripheral,Neurectomy, Laser,Neurectomy, Peripheral,Neurotomies, Radiofrequency,Neurotomy, Radiofrequency,Peripheral Neurectomies,Radiofrequency Neurotomies
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.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000831	Animals, Newborn	Refers to animals in the period of time just after birth.	Animals, Neonatal,Animal, Neonatal,Animal, Newborn,Neonatal Animal,Neonatal Animals,Newborn Animal,Newborn Animals
D001369	Axons	Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.	Axon
D013564	Sympathetic Nervous System	The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.	Nervous System, Sympathetic,Nervous Systems, Sympathetic,Sympathetic Nervous Systems,System, Sympathetic Nervous,Systems, Sympathetic Nervous
D015221	Potassium Channels	Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.	Ion Channels, Potassium,Ion Channel, Potassium,Potassium Channel,Potassium Ion Channels,Channel, Potassium,Channel, Potassium Ion,Channels, Potassium,Channels, Potassium Ion,Potassium Ion Channel