Biomaterial Database

The spinal reflex of chronic spinal rats is supersensitive to 5-HTP but not to TRH or 5-HT agonists. 1988

N Nagano, and H Ono, and M Ozawa, and H Fukuda

Department of Toxicology and Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.

The effects of thyrotropin-releasing hormone (TRH), 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) and L-5-hydroxytryptophan (5-HTP) were studied on the monosynaptic reflex (MSR) and the polysynaptic reflex (PSR) in acute and chronic spinal rats. Radioimmunoassay showed that while chronic spinal transection (for 2 weeks) caused the complete depletion of TRH in the ventral lumbar enlargement a certain level of TRH was maintained in the dorsal lumbar enlargement. This result suggested the existence of TRH-containing neurons in the dorsal horn other than the medullary raphe neurons descending to the spinal cord. The latency to the start of the MSR was shortened in chronic spinal rats and the amplitudes of the MSR and PSR were significantly greater than those in acute spinal rats. There was no obvious difference in the effects of TRH and 5-MeODMT on spinal reflexes of acute and of chronic spinal rats although marked supersensitivity to 5-HTP was observed in both the MSR and the PSR in chronic spinal rats. The supersensitivity to 5-HTP was considered to be due to a lack of 5-hydroxytryptamine (5-HT) uptake into 5-HT-containing nerve terminals rather than to a change in 5-HT receptors. It is suggested that TRH and 5-HT do not show any mutual requirement for each other in their effects on the spinal reflex since co-depletion of TRH and 5-HT did not change the effects of TRH and 5-MeODMT in chronic spinal rats. The coexistence of 5-HT and TRH in the descending spinal pathway is not considered to be significant for the control of spinal reflexes at the postsynaptic level.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008732	Methoxydimethyltryptamines	Compounds that contain the biogenic monoamine tryptamine and are substituted with one methoxy group and two methyl groups. Members of this group include several potent serotonergic hallucinogens found in several unrelated plants, skins of certain toads, and in mammalian brains. They are possibly involved in the etiology of schizophrenia.	Methylbufotenin,5-Methoxy-N,N-Dimethyltryptamine,Methoxydimethyltryptamine,N,N-Dimethyl-5-Methoxytryptamine,5 Methoxy N,N Dimethyltryptamine,N,N Dimethyl 5 Methoxytryptamine
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D011985	Receptors, Serotonin	Cell-surface proteins that bind SEROTONIN and trigger intracellular changes which influence the behavior of cells. Several types of serotonin receptors have been recognized which differ in their pharmacology, molecular biology, and mode of action.	5-HT Receptor,5-HT Receptors,5-Hydroxytryptamine Receptor,5-Hydroxytryptamine Receptors,Receptors, Tryptamine,Serotonin Receptor,Serotonin Receptors,Tryptamine Receptor,Tryptamine Receptors,Receptors, 5-HT,Receptors, 5-Hydroxytryptamine,5 HT Receptor,5 HT Receptors,5 Hydroxytryptamine Receptor,5 Hydroxytryptamine Receptors,Receptor, 5-HT,Receptor, 5-Hydroxytryptamine,Receptor, Serotonin,Receptor, Tryptamine,Receptors, 5 HT,Receptors, 5 Hydroxytryptamine
D012018	Reflex	An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
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
D003655	Decerebrate State	A condition characterized by abnormal posturing of the limbs that is associated with injury to the brainstem. This may occur as a clinical manifestation or induced experimentally in animals. The extensor reflexes are exaggerated leading to rigid extension of the limbs accompanied by hyperreflexia and opisthotonus. This condition is usually caused by lesions which occur in the region of the brainstem that lies between the red nuclei and the vestibular nuclei. In contrast, decorticate rigidity is characterized by flexion of the elbows and wrists with extension of the legs and feet. The causative lesion for this condition is located above the red nuclei and usually consists of diffuse cerebral damage. (From Adams et al., Principles of Neurology, 6th ed, p358)	Decerebrate Posturing,Decorticate Rigidity,Decorticate State,Rigidity, Decerebrate,Rigidity, Decorticate,Decerebrate Posturings,Decerebrate Rigidity,Decerebrate States,Decorticate Rigidities,Decorticate States,Posturing, Decerebrate,Posturings, Decerebrate,Rigidities, Decorticate,State, Decerebrate,States, Decerebrate
D006916	5-Hydroxytryptophan	The immediate precursor in the biosynthesis of SEROTONIN from tryptophan. It is used as an antiepileptic and antidepressant.	5-HTP,Hydroxytryptophan,Oxitriptan,Oxytryptophan,Tryptophan, 5-Hydroxy-,5 Hydroxytryptophan,5-Hydroxy- Tryptophan,Tryptophan, 5 Hydroxy
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