Biomaterial Database

Involvement of the dorsal raphe but not median raphe nucleus in morphine-induced increases in serotonin release in the rat forebrain. 1995

R Tao, and S B Auerbach

Department of Biological Sciences, Rutgers University, Piscataway, NJ 08855-1059, USA.

In vivo microdialysis was used to determine if morphine produces increases in extracellular serotonin in specific brain sites. With citalopram included in the dialysis solution to block reuptake, serotonin was measured in 11 brain sites of unanesthetized rats. After systemic morphine (10 mg/kg, s.c.), increases in extracellular serotonin were observed in the nucleus accumbens, amygdala, frontal cortex, striatum, thalamus, hypothalamus and ventral hippocampus. These seven areas are innervated either by dorsal raphe nucleus projections alone, or by projections from both dorsal and median raphe nucleus. In contrast, serotonin was not significantly increased in the medial septal nucleus and dorsal hippocampus. These two areas are selectively innervated by projections from the median raphe nucleus. After systemic morphine, serotonin was increased in the dorsal raphe nucleus, but not in the medial raphe nucleus. Local infusion of morphine through a microdialysis probe in the dorsal raphe nucleus induced a dose-dependent increase of serotonin in the nucleus accumbens, but not in the medial septum. In contrast, infusion of morphine into the median raphe nucleus had little effect on serotonin in either the nucleus accumbens or septum. Infusion of morphine into either the dorsal or median raphe nucleus elicited increased behavioral activity and hyperthermia. These data provide evidence that morphine acts in the area of the dorsal raphe nucleus, but not the median raphe nucleus, to enhance serotonin release in specific forebrain sites, and that the increases in serotonin in the dorsal raphe nucleus projection sites are not an indirect effect of changes in behavioral state or body temperature.

UI	MeSH Term	Description	Entries
D008297	Male		Males
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
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
D009292	Narcotic Antagonists	Agents inhibiting the effect of narcotics on the central nervous system.	Competitive Opioid Antagonist,Narcotic Antagonist,Opioid Antagonist,Opioid Antagonists,Opioid Receptor Antagonist,Opioid Reversal Agent,Competitive Opioid Antagonists,Opioid Receptor Antagonists,Opioid Reversal Agents,Agent, Opioid Reversal,Agents, Opioid Reversal,Antagonist, Competitive Opioid,Antagonist, Narcotic,Antagonist, Opioid,Antagonist, Opioid Receptor,Antagonists, Competitive Opioid,Antagonists, Narcotic,Antagonists, Opioid,Antagonists, Opioid Receptor,Opioid Antagonist, Competitive,Opioid Antagonists, Competitive,Receptor Antagonist, Opioid,Receptor Antagonists, Opioid,Reversal Agent, Opioid,Reversal Agents, Opioid
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
D001831	Body Temperature	The measure of the level of heat of a human or animal.	Organ Temperature,Body Temperatures,Organ Temperatures,Temperature, Body,Temperature, Organ,Temperatures, Body,Temperatures, Organ
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D005110	Extracellular Space	Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.	Intercellular Space,Extracellular Spaces,Intercellular Spaces,Space, Extracellular,Space, Intercellular,Spaces, Extracellular,Spaces, Intercellular
D006651	Histocytochemistry	Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.	Cytochemistry
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