Biomaterial Database

Serotonergic influence from nucleus raphe obscurus on neurones in the periaqueductal grey matter in the rat. 1993

T A Lovick

Department of Physiology, Medical School, University of Birmingham, UK.

In rats anaesthetised with urethane, iontophoretic application of 5-hydroxytryptamine (5-HT, 5-70 nA) produced changes in ongoing activity of 41/44 neurones in the periaqueductal grey matter (PAG). The majority (85%) of responsive cells were inhibited and 15% were excited. The inhibitions were mimicked in 5/7 cells by iontophoresis of the 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT, 10-30 nA) whilst excitation was produced in 3/5 cells by iontophoresis of the 5-HT2 agonist alpha-methyl-5-HT (10-30 nA). Selective activation of neuronal perikarya in nucleus raphe obscurus (NRO) by microinjection of 50-100 nl D,L-homocysteic acid (DLH) inhibited ongoing activity of 25/31 neurones tested in the PAG for periods of 30-580 s, mean 183.5 s. The duration of the inhibition was potentiated by between 36 and 300% during iontophoresis of the 5-HT re-uptake blocker paroxetine (1-25 nA, 6/6 cells). The results indicate that there is an extensive inhibitory serotonergic input to the PAG which originates, at least in part, from NRO.

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
D008297	Male		Males
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
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
D010487	Periaqueductal Gray	Central gray matter surrounding the CEREBRAL AQUEDUCT in the MESENCEPHALON. Physiologically it is probably involved in RAGE reactions, the LORDOSIS REFLEX; FEEDING responses, bladder tonus, and pain.	Mesencephalic Central Gray,Midbrain Central Gray,Central Gray Substance of Midbrain,Central Periaqueductal Gray,Griseum Centrale,Griseum Centrale Mesencephali,Periaqueductal Gray Matter,Substantia Grisea Centralis,Substantia Grisea Centralis Mesencephali,Central Gray, Mesencephalic,Central Gray, Midbrain,Gray Matter, Periaqueductal,Gray, Central Periaqueductal,Griseum Centrale Mesencephalus,Periaqueductal Grays, Central
D010879	Piperazines	Compounds that are derived from PIPERAZINE.
D011903	Raphe Nuclei	Collections of small neurons centrally scattered among many fibers from the level of the TROCHLEAR NUCLEUS in the midbrain to the hypoglossal area in the MEDULLA OBLONGATA.	Caudal Linear Nucleus of the Raphe,Interfascicular Nucleus,Nucleus Incertus,Rostral Linear Nucleus of Raphe,Rostral Linear Nucleus of the Raphe,Superior Central Nucleus,Central Nucleus, Superior,Incertus, Nucleus,Nuclei, Raphe,Nucleus, Interfascicular,Nucleus, Raphe,Nucleus, Superior Central,Raphe Nucleus
D002319	Cardiovascular System	The HEART and the BLOOD VESSELS by which BLOOD is pumped and circulated through the body.	Circulatory System,Cardiovascular Systems,Circulatory Systems
D006710	Homocysteine	A thiol-containing amino acid formed by a demethylation of METHIONINE.	2-amino-4-mercaptobutyric acid,Homocysteine, L-Isomer,2 amino 4 mercaptobutyric acid,Homocysteine, L Isomer,L-Isomer Homocysteine
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