Biomaterial Database

Non-dopaminergic mechanisms in the turning behavior evoked by intranigral opiates. 1985

M Morelli, and G Di Chiara

The turning effects of the unilateral intranigral injection of morphine and of different analogs of dynorphin and enkephalin were studied. All injections were made in awake rats through cronically implanted guide cannulae. Dynorphin1-13 at a dose of 10 micrograms (0.6 nmol) and dynorphin1-17 at a dose of 2 micrograms (0.9 nmol) produced contralateral circling when injected unilaterally in the substantia nigra (SN), lasting for about 1 h. D-Ala-dynorphin1-17, a more stable analog of dynorphin, produced at a dose of 2 micrograms (0.9 nmol), a longer-lasting effect. Injections of different enkephalin analogs were also made into the SN, [D-Ser2]-Leu-enkephalin (10 micrograms, 14.5 nmol) and [D-Ala2,D-Ala3]-Met-enkephalin (10 micrograms, 15 nmol) also produced contralateral circling after unilateral intranigral injection. This behavior lasted for 60-90 min, depending on the different enkephalins used. As already reported by Iwamoto and Way18 morphine also produced contralateral circling when injected into the SN. The circling evoked by all these opiates was completely antagonized by 5 mg/kg of naltrexone s.c. In order to study the role of the dopaminergic nigrostriatal system, we made unilateral lesions of the medial forebrain bundle (MFB) with 6-hydroxydopamine (6-OHDA) and kainic acid lesions of the striatum and we looked at the effect elicited by these lesions on the behavior produced by the above compounds when injected into the SN. The lesion of the dopaminergic nigrostriatal system failed to affect either the number of turns or the duration of the contralateral circling produced by unilateral injections of morphine, dynorphin and enkephalin analogs into the SN correspondent to the lesioned side. On the other hand kainate lesions of the body of the caudate potentiated the turning induced by intra-SN morphine and dynorphin. Therefore it appears that the dopaminergic nigrostriatal system is not essential in the expression of the contraversive turning behavior produced by intranigral injections of endogenous opiates or morphine and that opiates might produce dopamine-like effects indirectly, through the inhibition of nigral non-dopaminergic output neurons.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008474	Medial Forebrain Bundle	A complex group of fibers arising from the basal olfactory regions, the periamygdaloid region, and the septal nuclei, and passing to the lateral hypothalamus. Some fibers continue into the tegmentum.	Median Forebrain Bundle,Bundle, Medial Forebrain,Bundle, Median Forebrain,Bundles, Medial Forebrain,Bundles, Median Forebrain,Forebrain Bundle, Medial,Forebrain Bundle, Median,Forebrain Bundles, Medial,Forebrain Bundles, Median,Medial Forebrain Bundles,Median Forebrain Bundles
D009020	Morphine	The principal alkaloid in opium and the prototype opiate analgesic and narcotic. Morphine has widespread effects in the central nervous system and on smooth muscle.	Morphine Sulfate,Duramorph,MS Contin,Morphia,Morphine Chloride,Morphine Sulfate (2:1), Anhydrous,Morphine Sulfate (2:1), Pentahydrate,Oramorph SR,SDZ 202-250,SDZ202-250,Chloride, Morphine,Contin, MS,SDZ 202 250,SDZ 202250,SDZ202 250,SDZ202250,Sulfate, Morphine
D009068	Movement	The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.	Movements
D009271	Naltrexone	Derivative of noroxymorphone that is the N-cyclopropylmethyl congener of NALOXONE. It is a narcotic antagonist that is effective orally, longer lasting and more potent than naloxone, and has been proposed for the treatment of heroin addiction. The FDA has approved naltrexone for the treatment of alcohol dependence.	Antaxone,Celupan,EN-1639A,Nalorex,Naltrexone Hydrochloride,Nemexin,ReVia,Trexan,EN 1639A,EN1639A
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
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
D004399	Dynorphins	A class of opioid peptides including dynorphin A, dynorphin B, and smaller fragments of these peptides. Dynorphins prefer kappa-opioid receptors (RECEPTORS, OPIOID, KAPPA) and have been shown to play a role as central nervous system transmitters.	Dynorphin,Dynorphin (1-17),Dynorphin A,Dynorphin A (1-17)
D004745	Enkephalins	One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.	Enkephalin
D006892	Hydroxydopamines	Dopamines with a hydroxy group substituted in one or more positions.	Hydroxydopamine