Biomaterial Database

Microiontophoretic studies on noradrenergic inhibition from locus coeruleus of spinal trigeminal nucleus neurons. 1979

M Sasa, and S Fujimoto, and S Igarashi, and K Munekiyo, and S Takaori

Microiontophoretic studies using cats anesthetized with alpha-chloralose and local anaesthetic were undertaken in an attempt to determine whether or not norepinephrine (NE) derived from the locus coeruleus (LC) acts on neurons of the spinal trigeminal nucleus (STN) as an inhibitory transmitter. Both conditioning stimulation of the LC and iontophoretic application of NE inhibited orthodromic spike generation by interior alveolar nerve stimulation in 9 out of 14 STN relay neurons, without affecting antidromic spikes elicited by stimulation of the contralateral medial lemniscus. Glutamate-induced spike firing of the STN relay neurons, however, remained unaltered with iontophoretic application of NE up to 200 nA. The LC conditioning stimulation inhibited orthodromic spikes in 22 out of 25 type-B interneurons in the STN, while iontophoretic NE application seldom had an effect on orthodromic spikes and spontaneous firing of the interneurons. Only 5 out of the 25 interneurons exhibited an inhibition of orthodromic spike generation and spontaneous firing with iontophoretic NE. These neurons fired spikes upon orthodromic stimulation with a relatively short latency, compared with the spike latency of neurons unaffected by iontophoretic NE. The present results strongly suggest that NE released from the terminals of the LC neurons inhibits transmission of STN relay neurons, probably by acting on primary afferent terminals to produce presynaptic inhibition.

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
D008125	Locus Coeruleus	Bluish-colored region in the superior angle of the FOURTH VENTRICLE floor, corresponding to melanin-like pigmented nerve cells which lie lateral to the PERIAQUEDUCTAL GRAY.	Locus Caeruleus Complex,Locus Caeruleus,Locus Ceruleus,Locus Ceruleus Complex,Locus Coeruleus Complex,Nucleus Pigmentosus Pontis,Caeruleus Complex, Locus,Complex, Locus Caeruleus,Complex, Locus Ceruleus,Complex, Locus Coeruleus,Pontis, Nucleus Pigmentosus
D008297	Male		Males
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D009434	Neural Pathways	Neural tracts connecting one part of the nervous system with another.	Neural Interconnections,Interconnection, Neural,Interconnections, Neural,Neural Interconnection,Neural Pathway,Pathway, Neural,Pathways, 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
D009638	Norepinephrine	Precursor of epinephrine that is secreted by the ADRENAL MEDULLA and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the LOCUS CERULEUS. It is also found in plants and is used pharmacologically as a sympathomimetic.	Levarterenol,Levonorepinephrine,Noradrenaline,Arterenol,Levonor,Levophed,Levophed Bitartrate,Noradrenaline Bitartrate,Noradrénaline tartrate renaudin,Norepinephrin d-Tartrate (1:1),Norepinephrine Bitartrate,Norepinephrine Hydrochloride,Norepinephrine Hydrochloride, (+)-Isomer,Norepinephrine Hydrochloride, (+,-)-Isomer,Norepinephrine d-Tartrate (1:1),Norepinephrine l-Tartrate (1:1),Norepinephrine l-Tartrate (1:1), (+,-)-Isomer,Norepinephrine l-Tartrate (1:1), Monohydrate,Norepinephrine l-Tartrate (1:1), Monohydrate, (+)-Isomer,Norepinephrine l-Tartrate (1:2),Norepinephrine l-Tartrate, (+)-Isomer,Norepinephrine, (+)-Isomer,Norepinephrine, (+,-)-Isomer
D001933	Brain Stem	The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA.	Brainstem,Truncus Cerebri,Brain Stems,Brainstems,Cerebri, Truncus,Cerebrus, Truncus,Truncus Cerebrus
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
D005260	Female		Females