Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Agonistic Behavior”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed2005

Chronic administration of the delta opioid receptor agonist (+)BW373U86 and antidepressants on behavior in the forced swim test and BDNF mRNA expression in rats.

RATIONALE: Selective delta opioid receptor agonists have been shown to produce antidepressant-like behavioral effects and increase brain-derived neurotrophic factor (BDNF) mRNA expression when given acutely, but the chronic effects of delta agonists have been less well characterized. OBJECTIVE: The present study examined the effects of chronic exposure to the delta agonist (+)BW373U86 (BW) on antidepressant-like behavior in the forced swim test and on BDNF mRNA expression in comparison to chronic treatment with the antidepressants fluoxetine, desipramine, bupropion, and tranylcypromine. METHODS: Sprague-Dawley rats were treated chronic ally with one of the above treatments and were tested for antidepressant effects in the forced swim test, and assayed for BDNF mRNA expression by in situ hybridization. RESULTS: Acute administration of 10 mg/kg BW produced a significant antidepressant-like effect in the forced swim test, while chronic (8- or 21-day) BW administration did not produce a significant antidepressant-like effect. When 10 mg/kg BW was administered for 8 days, it produced a significant increase in BDNF mRNA expression in the frontal cortex, while having no effect on BDNF expression when given for 21 days. Chronic bupropion and desipramine significantly decreased BDNF expression in the dentate gyrus of the hippocampus, while fluoxetine had no effect in any brain region. Chronic tranylcypromine produced a significant increase in BDNF expression in the CA1 region of the hippocampus. CONCLUSIONS: Chronic exposure to BW produces tolerance to most effects, although at differential rates. In addition, increased BDNF mRNA expression does not appear to be a common effect of chronic administration of various antidepressants.

Animals↗
PubMed1992

Combination of a delta opioid receptor agonist but not a mu opioid receptor agonist with the D1-selective dopamine receptor agonist SKF 38393 markedly potentiates different behaviors in mice.

The effects of intracerebroventricular injections of opioid peptides selective for mu or delta opioid receptors on behaviors induced by the D1 dopamine agonist SKF 38393 were investigated by using multi-dimensional behavioral analyses. A 10.0 mg/kg dose of SKF 38393 produced a marked increase in grooming behavior. The SKF 38393 (10.0 mg/kg)-induced increase in grooming behavior was clearly antagonized by SCH 23390 (0.03 mg/kg), a D1 dopamine antagonist, but not by S(-)-sulpiride (10.0 mg/kg), a D2 dopamine antagonist. [D-Ala2,MePhe4,Gly5-ol]enkephalin (DAMGO) (0.003 and 0.01 microgram), a mu-selective agonist, or [D-Pen2,L-Pen5]enkephalin (DPLPE) (0.3 or 1.0 microgram), a delta-selective agonist, failed to affect spontaneous behaviors. The combination of DPLPE (0.3 and 1.0 microgram) but not of DAMGO (0.003 and 0.01 microgram) with SKF 38393 (10.0 mg/kg) produced a marked increase in linear locomotion and circuling away from the side receiving the peptide, whereas grooming behavior was not affected. The effects induced by DPLPE (1.0 microgram) plus SKF 38393 (10.0 mg/kg) were fully reversed by the delta-selective opioid antagonist naltrindole (10.0 mg/kg), SCH 23390 (0.03 mg/kg) and S(-)-sulpiride (10.0 mg/kg). These findings suggest that delta but not mu opioid systems interact with D1 dopamine receptors, resulting in a marked increase in linear locomotion and contralateral circuling without causing marked changes in grooming behavior.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMedDate not supplied

[The effect of DAGO, selective milli-opioid receptor agonist, on hostile and anxious behaviors in male mice with different experience of aggression].

Effects of mu-opioid receptor agonist DAGO (2.0 mg/kg, s.c.) on anxioUs, hostile, and aggressive behaviors of male mice with repeated 3- and 20-day experience of aggression accompanied by victories (T3 and T20 winners, respectively) were stUdied. T20 winners showed lower aggression (attacking and biting) and hostile behavior and were more anxioUs (estimated by plUs-maze test) than T3 winners. In the plUs-maze test DAGO prodUced anxiogenic effects in intact males and was ineffective in T3 and T20 winners testifying to a decrease in mu-receptor sensitivity Under the inflUence of repeated aggression. In agonistic confrontation test, DAGO increased aggressive grooming in T20 winners, decreased hostile behavior (digging and throwing partner's litter) in T3 winners, and did not inflUence attacks in both groUps. It is sUggested that mu-opioid receptors are involved into forming the aggressive behavioral type in mice, and DAGO effects may be conditioned by emotional backgroUnd of these behavioral forms.

Aggression↗
PubMed1985

Behavior and growth parameters of large white turkeys as affected by floor space and beak trimming. II. Females.

The effects of floor space allowance and beak trimming on behavior and growth performance of female Large White turkeys were studied. Floor space allowances were 5.6, 7.0, and 9.3 dm2/bird from 0 to 8 weeks of age and 14.0, 18.6, and 23.2 dm2/bird from 8 to 16 weeks of age. Floor space was adjusted by changing pen size to assure a constant number of birds per pen. Results showed that neither floor space allowance nor beak trimming had any significant effect of any of the variables under study through 8 weeks of age. At 16 weeks of age, growth, feed consumption, feed efficiency, feather scores, live market quality grades, and mortality were still unaffected. Beak trimming significantly reduced body weight gain, body weight, and feed consumption but had no significant effect on feed efficiency, feather scores, or mortality. Agonistic (aggressive) behavior was very low in this population of females. Of significance, however, were the nonaggressive behaviors of social "pecking" and "pecking and pulling" of feathers. Feather-pecking activity was unaffected by previous or subsequent floor space allowances through 16 weeks of age; however, the incidence of pecking and pulling of feathers was highest among females previously assigned the largest floor space allowance (9.3 dm2/bird) in the brooder house and subsequently allowed the smallest floor space allowance (14.0 dm2/bird) in the grower house. Beak trimming significantly increased the frequency of both "pecking" and "pecking and pulling" of feathers over that of their untrimmed contemporaries when the females were 12 and 16 weeks of age. Possible reasons for this are discussed.

Aggression↗
PubMedDate not supplied

Misbehaving physicians and professional ethics.

Consider a true story about physician misbehavior and see how it was handled. Sometimes a gentle touch works well in situations of unexpected and unintended behavioral problems.

Agonistic Behavior↗
PubMed1985

Predictors of dominance in male Betta splendens.

The formation of dominance/subordinancy relations in pairs of male Siamese fighting fish was examined in six experiments. Dominant animals typically were those fish that built the largest nests and that attacked an image of a live, displaying male most intensely prior to combat. However, pretest performance on an operant task and reaction to an animal's own mirror image were not useful predictors of subsequent dominance. These findings are consistent with the suggestion that domesticated Bettas have a territorial social strategy that includes both nest-building and fighting behaviors.

Aggression↗
PubMed1996

Differential behavioral response to dopamine D2 agonists by sexually naive, sexually active, and sexually inactive male rats.

This study was performed with male rats categorized as sexually naive (SN), sexually active (SA), or sexually inactive (SI). In a first experiment the effects of dopamine (DA) D2 agonist SND 919 (0.05, 1, and 10 mg/kg) on the copulatory behavior of SN, SA and SI rats were assessed. In a second experiment the DA D2 agonist B-HT 920 (0.2 mg/kg) was used, and examination was limited to SN and SA rats. The effects exerted on stretching-yawning, penile erection, and sedation by the same compounds at the same doses in these three rat categories were also investigated. The main findings were that SND 919 and B-HT 920 facilitated ejaculation in SA rats, and that the rats that were different as regards level of sexual activity exhibited different behavioral responses to the two DA agonists.

Animals↗
PubMed1991

Effects of 5-HT-1A receptor agonists on CRF-induced behavior.

Buspirone (2.0 or 4.0 mg/kg) and 8-hydroxy-2-(di-N-propylamino)-tetralin (8-OH-DPAT) (0.25 or 0.5 mg/kg) were used to examine the effects of serotonin 1A receptor agonists on the behavioral response of rats to centrally administered corticotropin-releasing factor (CRF). Behavioral observations were done with animals in their home cages. Parameters measured included locomotor activity, grooming and food consumption. CRF alone increased locomotor activity. 8-OH-DPAT also increased locomotion in both saline control and CRF-treated rats. Buspirone had no effect on basal locomotion or on CRF-induced hyperactivity. Both buspirone and 8-OH-DPAT antagonized CRF-induced grooming. Food consumption by fasted rats was suppressed by ICV CRF. 8-OH-DPAT suppressed eating by both ICV CRF and ICV saline-treated animals, while buspirone was without effect. These results demonstrate differences between the two putative 5-HT-1A agonists in their effects on CRF-induced behaviour but also demonstrate that both suppress CRF-induced grooming.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2004

Trypsin mediates nociception via the proteinase-activated receptor 2: a potentially novel role in pancreatic pain.

BACKGROUND & AIMS: The pathogenesis of pain in pancreatitis remains poorly understood. We hypothesized that trypsin, a key inflammatory mediator in this condition, can also activate nociceptive neurons via the proteinase-activated receptor 2. METHODS: Double immunohistochemical staining of T8 to T12 dorsal root ganglia sections was performed with antibodies against proteinase-activated receptor 2 and vanilloid receptor 1, a marker for primary nociceptive neurons. In vivo nociceptive activity was measured by FOS immunoreactivity in thoracic spinal dorsal horn segments after intrapancreatic administration of proteinase-activated receptor 2 agonists. Pain behavior was assessed by visceromotor reflex activity in response to noxious stimulation of the pancreas with proteinase-activated receptor 2 agonists. RESULTS: Proteinase-activated receptor 2 was expressed by virtually all nociceptive neurons in thoracic dorsal root ganglia. Intraductal trypsin, in subinflammatory concentrations, activated spinal dorsal horn neurons in a dose-dependent manner, as measured by FOS expression. Both trypsin and a proteinase-activated receptor 2-specific peptide agonist induced a behavioral pain response when infused into the pancreatic duct of awake rats. Preinfusion of the pancreatic duct with proteinase-activated receptor 2-specific activating peptide desensitized the response to trypsin. CONCLUSIONS: Our findings suggest a novel proteinase-activated receptor 2-mediated role for trypsin in the pathogenesis of pancreatic pain and one that is independent of its inflammatory effect.

Animals↗
PubMed1990

Hormonal regulation of sociosexual behavior in female mammals.

The role of estrogen (E) and progesterone (P) in regulating the expression of agonistic, scent marking and proceptive displays is reviewed. In the intact sexually mature female, data indicate that agonistic, scent marking and proceptive patterns of behavior fluctuate significantly prior to and during the period of mating. The propensity to display a specific pattern of behavior is dependent upon the stimulus situation. Hence, agonistic behavior may be induced by the presence of a conspecific female whereas sexual behavior and proceptive responses will be elicited by a male. Administration of E to ovariectomized animals does not appear to produce significant effects on agonistic behavior and territorial scent-marking responses albeit in a few cases E appears to reduce agonistic tendencies toward male conspecifics. Exogenous E treatment, however, does appear to induce the occurrence of proceptive forms of scent-marking behavior as well as a variety of other proceptive responses which are further increased after P treatment. Importantly, the sequential administration of E and P facilitates both proceptive and copulatory responses in several rodent species. In addition, hormone implant studies indicate that sites in the brain which are sensitive to the hormonal facilitation of sexual receptivity concurrently facilitate proceptive behavior. On the basis of the current data, ovarian hormones appear to exert their strongest effects on producing behavioral displays which attract males prior to mating, facilitating sexual receptivity, and inducing concurrently proceptive responses which further enhance copulation and reproductive success.

Animals↗
PubMed1998

Opiate agonist-induced changes in behavioral sensitivity to clonidine are observed in perinatally malnourished rats exposed to chronic stress.

Sensitivity of alpha2-adrenoceptors following repeated immobilization sessions plus morphine (MOR) or beta-endorphin (BETA) was assayed by examining clonidine (CLO)-induced hypoactivity in adult malnourished rats at perinatal age. As previously described, chronic restraint did not attenuate the hypoactivity elicited by CLO in malnourished rats, although chronic restraint did have such an effect on motor activity in control animals. MOR and BETA administration prior to each restraint session induced subsensitivity of alpha2-adrenoceptors in malnourished rats as determined by a blunted response to clonidine challenge. An injection of naloxone (NAL) prior to BETA before each stress session fully antagonized the subsensitivity to clonidine observed in malnourished animals. A possible deficiency in the functional role of the opiate system in the process of adaptation to chronic stress in perinatal malnourished rats is suggested.

Adrenergic alpha-Agonists↗
PubMed1992

Constriction of environmental space and the behavioral response to the dopamine agonist quinpirole.

The present study examines the influence of size of testing environment on the behavioral profile seen following injection of the dopamine D2 receptor agonist quinpirole (0.5 mg/kg, n = 16) or saline (n = 16). All rats were tested in a counterbalanced order in both a small and large environment. Oral (licking) behaviors were observed exclusively in the small environment and only in drug-treated rats; moreover, quinpirole increased rearing in the small but not large environment. Other behaviors--sniffing, face and body grooming--were affected by quinpirole but not in an environment-dependent manner. It is concluded that limiting environmental space promotes emergence of oral responding under quinpirole. The self-directed nature of this licking (paw- and tail-licking) may reflect a hierarchical transformation of quinpirole-induced hyperactivity from exploration of space to investigation of body parts.

Animals↗
PubMed1988

Behavior induced by putative nociceptive neurotransmitters is inhibited by adenosine or adenosine analogs coadministered intrathecally.

Adenosine agonists administered systemically, intracerebroventricularly and intrathecally have been demonstrated to induce antinociception. Results from studies utilizing intrathecal administration of adenosine or adenosine analogs, in particular, suggest that endogenous adenosine may inhibit the transmission of nociceptive impulses at spinal sites. The present investigations were performed to extend our understanding of the role of adenosine in antinociception by examining the effect of adenosine agonists on behavior induced by two putative spinal nociceptive neurotransmitters, substance P and N-methyl-D-aspartate. Coadministration of each of several adenosine agonists with substance P or N-methyl-D-aspartate intrathecally significantly decreased the intensity of behaviors induced by putative nociceptive neurotransmitters in mice. Adenosine agonist-mediated inhibition was antagonized by theophylline supporting adenosine agonist interactions with cell membrane surface adenosine receptors. Rank order potencies were determined for several adenosine analogs with varying selectivity for A1 and A2 adenosine receptor subtypes. However, rank order potencies did not correlate well with rank order potencies reported previously for adenosine receptor subtypes in biochemical assays. The results of these investigations demonstrate that adenosine inhibits behavior induced by nociceptive neurotransmitters interacting with spinal substance P or N-methyl-D-aspartate receptors. Furthermore, observations provide additional support for endogenous antinociceptive pathways that utilize adenosine at spinal sites.

Adenosine↗