Biomaterial Database

Opioid stimulation in the ventral tegmental area facilitates the onset of maternal behavior in rats. 1996

A C Thompson, and M B Kristal

Department of Psychology, State University of New York at Buffalo 14260, USA. athompso@irp.nida.nih.gov

This research investigated the effect of an increase or decrease in opioid activity in the ventral tegmental area (VTA) on the onset of maternal behavior in rats. In Experiment 1, the latency to show maternal behavior toward foster rat pups (sensitization latency) was determined in maternally naive female rats given either nothing or a unilateral intra-VTA injection of morphine sulfate (MS) (0.0, 0.01, 0.03, 0.1 or 0.3 microgram), on the first three days of a 10-day period of constant exposure to pups. Rats treated with 0.03 microgram MS had significantly shorter sensitization latencies than did rats treated with 0.0 microgram MS, 0.01 microgram MS, or receiving no treatment (higher doses of morphine produced intermediate results). The facilitating effect of intra-VTA MS on the onset of maternal behavior was blocked by pretreatment with naltrexone hydrochloride and was found to have a specific site of action in the VTA (MS injections dorsal to the VTA were ineffective). In Experiment 2, sensitization latencies were determined in periparturitional rats given a bilateral intra-VTA injection of either the opioid antagonist naltrexone methobromide (quaternary naltrexone), its vehicle, a sham injection, or left untreated 40 min after delivery of the last pup. The mothers' own pups were removed at delivery; mothers were nonmaternal at the time of testing. Quaternary naltrexone treatment produced significantly slower sensitization to foster pups than did control conditions. Total activity and pup-directed activity did not differ significantly with treatment. The results demonstrate that increased opioid activity in the VTA facilitates the onset of maternal behavior in inexperienced nonpregnant female rats, and decreased opioid activity in the VTA disrupts the rapid onset of maternal behavior at parturition.

UI	MeSH Term	Description	Entries
D008425	Maternal Behavior	The behavior patterns associated with or characteristic of a mother.	Maternal Patterns of Care,Maternal Care Patterns,Behavior, Maternal,Behaviors, Maternal,Care Pattern, Maternal,Care Patterns, Maternal,Maternal Behaviors,Maternal Care Pattern,Pattern, Maternal Care,Patterns, Maternal Care
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
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
D005260	Female		Females
D000701	Analgesics, Opioid	Compounds with activity like OPIATE ALKALOIDS, acting at OPIOID RECEPTORS. Properties include induction of ANALGESIA or NARCOSIS.	Opioid,Opioid Analgesic,Opioid Analgesics,Opioids,Full Opioid Agonists,Opioid Full Agonists,Opioid Mixed Agonist-Antagonists,Opioid Partial Agonists,Partial Opioid Agonists,Agonist-Antagonists, Opioid Mixed,Agonists, Full Opioid,Agonists, Opioid Full,Agonists, Opioid Partial,Agonists, Partial Opioid,Analgesic, Opioid,Full Agonists, Opioid,Mixed Agonist-Antagonists, Opioid,Opioid Agonists, Full,Opioid Agonists, Partial,Opioid Mixed Agonist Antagonists,Partial Agonists, Opioid
D000704	Analysis of Variance	A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.	ANOVA,Analysis, Variance,Variance Analysis,Analyses, Variance,Variance Analyses
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
D013268	Stimulation, Chemical	The increase in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.	Chemical Stimulation,Chemical Stimulations,Stimulations, Chemical