Biomaterial Database

Effect of inhibitory amino acid antagonists on masseteric reflex suppression during active sleep. 1987

P J Soja, and D M Finch, and M H Chase

We examined the pharmacological basis for the suppression of the masseteric (jaw-closer) reflex which occurs during the behavioral state of active sleep. Accordingly, the masseteric reflex was recorded in intact, unanesthetized, normally respiring cats during naturally occurring states of wakefulness and active sleep. The amplitude of the reflex during these states was determined before and after strychnine, picrotoxin, and bicuculline methiodide were applied, by microinjection, to the trigeminal motor nucleus. The effectiveness of each drug in blocking the active sleep-related suppression of the masseteric reflex was examined and compared with the degree of suppression evoked, during wakefulness, by stimulation of the inferior alveolar nerve. Microinjection of strychnine (50 microM to 20 mM) reduced the degree of suppression of the masseteric reflex during active sleep, but was markedly more effective in blocking reflex suppression that was induced by stimulating the inferior alveolar nerve. Picrotoxin and bicuculline methiodide (10 microM to 5 mM) produced a nonspecific increase in the amplitude of the masseteric reflex during both states. Thus, these substances did not appear to reduce the degree of reflex suppression induced by inferior alveolar nerve stimulation or that occurring spontaneously during active sleep. We concluded that strychnine-sensitive postsynaptic inhibition does participate in the suppression of masseter motor activity during active sleep, but that it is not the exclusive factor responsible for atonia of the masseter musculature during this state.

UI	MeSH Term	Description	Entries
D008410	Masticatory Muscles	Muscles arising in the zygomatic arch that close the jaw. Their nerve supply is masseteric from the mandibular division of the trigeminal nerve. (From Stedman, 25th ed)	Masticatory Muscle,Muscle, Masticatory,Muscles, Masticatory
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
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
D012023	Reflex, Monosynaptic	A reflex in which the AFFERENT NEURONS synapse directly on the EFFERENT NEURONS, without any INTERCALATED NEURONS. (Lockard, Desk Reference for Neuroscience, 2nd ed.)	Monosynaptic Reflex
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
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
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
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
D001640	Bicuculline	An isoquinoline alkaloid obtained from Dicentra cucullaria and other plants. It is a competitive antagonist for GABA-A receptors.	6-(5,6,7,8-Tetrahydro-6-methyl-1,3-dioxolo(4,5-g)isoquinolin-5-yl)furo(3,4-e)1,3-benzodioxol-8(6H)one
D012894	Sleep Stages	Periods of sleep manifested by changes in EEG activity and certain behavioral correlates; they formerly included Stage 1: sleep onset, drowsy sleep; Stage 2: light sleep; Stages 3 and 4: delta sleep, light sleep, deep sleep, telencephalic sleep. In 2007, sleep stages were redefined by The American Academy of Sleep Medicine (AASM) as: N1-N2 (sleep onset - light sleep), N3 (SLOW-WAVE SLEEP), and REM SLEEP.	N1-Sleep,N2-Sleep,NREM Stage 1,NREM Stage 2,N1 Sleep,N2 Sleep,Sleep Stage,Stage, Sleep,Stages, Sleep