Biomaterial Database

Evidence that glycine mediates the postsynaptic potentials that inhibit lumbar motoneurons during the atonia of active sleep. 1989

M H Chase, and P J Soja, and F R Morales

Department of Physiology, UCLA School of Medicine 90024.

Postsynaptic inhibition of somatic motoneurons underlies the atonia of active sleep. This inhibitory control depends, in large measure, on the bombardment of motoneurons during active sleep by a unique class of large-amplitude inhibitory postsynaptic potentials (IPSPs). These potentials are present only during this behavioral state and have therefore been designated as active sleep-specific IPSPs (AS-IPSPs). The present study was concerned with determining the neurotransmitter that mediates these AS-IPSPs. Lumbar motoneurons were recorded intracellularly during quiet and active sleep in intact, undrugged, normally respiring cats. The frequency and waveform parameters of the inhibitory postsynaptic potentials recorded from these motoneurons were examined following the microiontophoretic juxta-cellular administration of strychnine (a glycine receptor antagonist) and picrotoxin and bicuculline (GABA receptor antagonists). Microiontophoretically applied strychnine abolished the AS-IPSPs and a majority of smaller-amplitude IPSPs. Neither picrotoxin nor bicuculline modified the frequency, amplitude, or rising phase of the AS-IPSPs or the smaller-amplitude IPSPs. We conclude that the postsynaptic inhibitory drive that impinges on motoneurons during active sleep is principally mediated by glycine or a glycinergic substance.

UI	MeSH Term	Description	Entries
D007478	Iontophoresis	Therapeutic introduction of ions of soluble salts into tissues by means of electric current. In medical literature it is commonly used to indicate the process of increasing the penetration of drugs into surface tissues by the application of electric current. It has nothing to do with ION EXCHANGE; AIR IONIZATION nor PHONOPHORESIS, none of which requires current.	Iontophoreses
D008161	Lumbosacral Region	Region of the back including the LUMBAR VERTEBRAE, SACRUM, and nearby structures.	Lumbar Region,Lumbar Regions,Lumbosacral Regions,Region, Lumbar,Region, Lumbosacral,Regions, Lumbar,Regions, Lumbosacral
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
D009129	Muscle Tonus	The state of activity or tension of a muscle beyond that related to its physical properties, that is, its active resistance to stretch. In skeletal muscle, tonus is dependent upon efferent innervation. (Stedman, 25th ed)	Muscle Tension,Muscle Tightness,Muscular Tension,Tension, Muscle,Tension, Muscular,Tightness, Muscle,Tonus, Muscle
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D010852	Picrotoxin	A mixture of PICROTOXININ and PICROTIN that is a noncompetitive antagonist at GABA-A receptors acting as a convulsant. Picrotoxin blocks the GAMMA-AMINOBUTYRIC ACID-activated chloride ionophore. Although it is most often used as a research tool, it has been used as a CNS stimulant and an antidote in poisoning by CNS depressants, especially the barbiturates.	3,6-Methano-8H-1,5,7-trioxacyclopenta(ij)cycloprop(a)azulene-4,8(3H)-dione, hexahydro-2a-hydroxy-9-(1-hydroxy-1-methylethyl)-8b-methyl-, (1aR-(1aalpha,2abeta,3beta,6beta,6abeta,8aS,8bbeta,9S))-, compd. with (1aR-(1aalpha,2abeta,3beta,6beta,6abeta,8,Cocculin
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
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.
D005998	Glycine	A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.	Aminoacetic Acid,Glycine, Monopotassium Salt,Glycine Carbonate (1:1), Monosodium Salt,Glycine Carbonate (2:1), Monolithium Salt,Glycine Carbonate (2:1), Monopotassium Salt,Glycine Carbonate (2:1), Monosodium Salt,Glycine Hydrochloride,Glycine Hydrochloride (2:1),Glycine Phosphate,Glycine Phosphate (1:1),Glycine Sulfate (3:1),Glycine, Calcium Salt,Glycine, Calcium Salt (2:1),Glycine, Cobalt Salt,Glycine, Copper Salt,Glycine, Monoammonium Salt,Glycine, Monosodium Salt,Glycine, Sodium Hydrogen Carbonate,Acid, Aminoacetic,Calcium Salt Glycine,Cobalt Salt Glycine,Copper Salt Glycine,Hydrochloride, Glycine,Monoammonium Salt Glycine,Monopotassium Salt Glycine,Monosodium Salt Glycine,Phosphate, Glycine,Salt Glycine, Monoammonium,Salt Glycine, Monopotassium,Salt Glycine, Monosodium
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