Biomaterial Database

Feedback loop between locus coeruleus and spinal trigeminal nucleus neurons responding to tooth pulp stimulation in the rat. 1979

S Igarashi, and M Sasa, and S Takaori

Studies were performed to elucidate reciprocal relationships between locus coeruleus (LC) and spinal trigeminal nucleus (STN) neurons responding to tooth pulp (TP) stimulation using rats anesthetized with alpha-chloralose. LC conditioning stimulation inhibited STN field potential as well as orthodromic spike generation of STN neurons produced by ipsilateral TP stimulation, confirming the previous findings in cats that LC neurons played an inhibitory role in the orthodromic transmission in STN neurons. Forty-one out of 56 LC neurons were activated by ipsilateral TP stimulation and 12 neurons by stimulation of both ipsi- and contralateral TP. STN stimulation usually excited LC neurons with a significantly shorter latency than did TP stimulation, including three LC neurons with a latency of less than 2.0 msec. These results indicate the existence of input from TP to LC neurons via multisynapses. In addition, neurons antidromically activated by STN stimulation were found in LC. It is highly probable, therefore, that there is a feedback loop between LC and STN, which might control input from TP to STN.

UI	MeSH Term	Description	Entries
D007395	Interneurons	Most generally any NEURONS which are not motor or sensory. Interneurons may also refer to neurons whose AXONS remain within a particular brain region in contrast to projection neurons, which have axons projecting to other brain regions.	Intercalated Neurons,Intercalated Neuron,Interneuron,Neuron, Intercalated,Neurons, Intercalated
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
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
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
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D003213	Conditioning, Psychological	Simple form of learning involving the formation, strengthening, or weakening of an association between a stimulus and a response.	Conditioning, Psychology,Psychological Conditioning,Social Learning Theory,Social Learning Theories,Theory, Social Learning
D003782	Dental Pulp	A richly vascularized and innervated connective tissue of mesodermal origin, contained in the central cavity of a tooth and delimited by the dentin, and having formative, nutritive, sensory, and protective functions. (Jablonski, Dictionary of Dentistry, 1992)	Dental Pulps,Pulp, Dental,Pulps, Dental