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 703 records · Page 39Linked to original sources
PubMed1999

Effects of trkB and trkC neurotrophin receptor agonists on thermal nociception: a behavioral and electrophysiological study.

Nerve-growth factor (NGF), a member of the neurotrophin family, plays an important role in nociceptor function. Prompted by a previous uinexpected finding that NT-4/5, as well as NGF sensitizes single nociceptors to noxious heat, we have explored the relative potency of all neurotrophins in eliciting thermal hyperalgesia. NGF, brain-derived neurotrophic factor (BDNF), NT-4/5 and NT-3 were injected locally into the hind paw of rats, and the behavioral response to noxious heat was compared with that from the other paw that received an identical injection of vehicle. Like NGF, agonists of tyrosine kinaseB (trkB) receptors (NT-4/5 and BDN F) induced thermal hyperalgesia in the first 5 h after treatment (NT-4/5 > BDNF) but the effect had worn off by 24 h. In contrast, the trkC agonist NT-3 had no effect on the response to noxious heat. Electrophysiological recordings from single C-fibres in the in vitro skin-saphenous nerve preparation revealed sensitization to noxious heat stimuli after direct application of BDNF to the receptive field, as previously noted for NT-4/5, and in parallel with the behavioral findings. NT-3 was ineffective as in the behavioral studies. These results suggest that trkB agonists BDNF and NT-4/5 as well as the trkA agonist NGF can regulate nociceptive responses to noxious heat.

Animals↗
PubMed1996

Involvement of the 5-HT1A subtype receptor in the neonatal organization of agonistic behaviour in the rat.

5-hydroxytryptamine (5-HT) interacts with testosterone (T) in the development of a number of neuronal systems controlling sexually dimorphic adult behaviours. In this report, we investigated this interaction on the organization of agonistic behaviour in males, females, androgenized females (250 micrograms/pup of T proprionate on the day of birth), and males castrated on the day of birth. We have shown previously that manipulating 5-HT2 activity over the 2nd week of life modulates adult agonistic behaviour, depending on genetic sex and the presence of T. In this report, we investigated the effects seen in adulthood of a 5-HT1A agonist [8-OH-DPAT, 0.25 mg/kg, intraperitoneally (i.p.)] and antagonist (WAY100135, 0.25 mg/kg, i.p.) given over days 8-16 postpartum. The test for agonistic behaviour was carried out in a neutral territory against a matched conspecific, and introductory, offensive and defensive activities were note. Results show that neonatal administration of the 5-HT1A antagonist WAY100135 increases introductory activity and defense in the presence of neonatal T, independent of genetic sex, because these effects were seen in sham-castrated males and androgenized females. Offence followed a similar pattern, in that it was increased by WAY100135, but only in males. In the case of defence, the effects of the antagonist were reinforced by the action of the agonist (8-OH-DPAT) in both males and females, indicating an inhibitory role of 5-HT1A perinatal activity on defence in the presence of malelike levels of circulating T and a facilitatory role when levels of T are low or negligible. These findings indicate that 5-HT1A activity is involved in the development of agonistic behaviour and the effects are influenced by T. The results also show that the offensive and defensive facets of agonistic activity are controlled differently.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1991

Interaction of haloperidol and SCH 23390 with cocaine and dopamine receptor subtype-selective agonists on schedule-controlled behavior of squirrel monkeys.

Involvement of D1 and D2 dopamine receptors in the effects of cocaine on schedule-controlled behavior was evaluated in squirrel monkeys responding under a multiple fixed-interval 5-min, fixed-ratio 10 schedule (mult FI FR) of food delivery. Cocaine and the D2 agonist quinpirole increased responding under the F1 at certain doses and disrupted the temporal patterning of behavior. Higher doses of these drugs decreased responding. In contrast, the D1 agonist SKF 38393 was devoid of behavioral activity up to 10 mg/kg where response suppression was obtained without significant modification of the temporal distribution of responding. The D2 antagonist haloperidol (0.001-0.03 mg/kg) did not alter the behavioral effects of cocaine up to doses that had pronounced behavioral effects on their own. However, haloperidol attenuated the behavioral effects of quinpirole. In contrast, the D1 antagonist SCH 23390 partially attenuated the response rate-suppressant effects of cocaine without blocking cocaine-induced disruptions of temporal response patterning. SCH 23390 did not antagonize the behavioral effects of SKF 38393. These results suggest that independent stimulation of either D1 or D2 receptors alone does not play a major role in the effects of cocaine on schedule-controlled behavior of squirrel monkeys.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1992

Differential effects of serotonergic and catecholaminergic drugs on ingestive behavior.

The serotonergic agonists fenfluramine and fluoxetine and the catecholaminergic agonists amphetamine and phenylpropanolamine are well known to cause a reduction in intake in rats. In the studies reported here we investigated the effects of these drugs on the microstructure of licking behavior of the rat ingesting 0.4 M sucrose. The purpose was to examine the similarities in the behavioral effects within and between these two classes of anorectic agents. The serotonergic agonists fenfluramine and fluoxetine caused a reduction in intake primarily by reducing the size of bursts and clusters of licking within the test meal without affecting the duration of the meal, suggesting a reduction in the palatability of the test solution. The catecholamine agonists amphetamine and phenylpropanolamine reduced intake primarily by reducing the number of bursts and clusters without affecting their size, suggesting a fractionation in the organization of the normal pattern of ingestion. The differences between the two serotonin and the two catecholamine agonists on the microstructure of the licking behavior suggest a different effect of the two neurotransmitters on the motor system that controls ingestive behavior. The similarities between the two different agonists within each class suggests a common neurotransmitter mechanism responsible for these two different effects on the behavior of the animals.

Animals↗
PubMed1984

Inhibition of locomotor activity during cholinergically-induced emotional-aversive response in the cat.

Unilateral injections of carbachol (CCh, 10 micrograms) into the anterior hypothalamic/preoptic area of cats caused an inhibition of locomotor activity measured in two different ways in 4-field and 100-field activity boxes. This inhibition was accompanied by crouched posture of the cat's body, general arousal with increased number of searching head movements, autonomic manifestations, and vocalization. Recordings of the growling component of vocalization, serving as a quantitative index of CCh-induced emotional-aversive response, showed that the period of maximal inhibition of locomotor activity coincided with the peak values of vocalization. We conclude that direct injections of CCh into the anterior hypothalamic/preoptic area in cats activate a central mechanism responsible for an inhibition of locomotor activity. This inhibition seems to be one of the natural components of defensive responses, further supporting the suggestion that the CCh-induced emotional-aversive response is equivalent to naturally occurring defensive behavior in cats.

Agonistic Behavior↗
PubMed2005

A battery of olfactory-based screens for phenotyping the social and sexual behaviors of mice.

We provide a battery of screens that reflect the social and sexual behavior displayed by both captive and feral mice. Some screens focus on measuring aspects of chemical communication, providing information about whether or not mice will interact and if they do so, predict the nature of the interaction. Other screens measure direct interactions between target mice and same- and opposite-sex conspecifics, providing an indication of the social status and sexual responsiveness, respectively, of target mice. The battery of screens yields a high-throughput bioassay of a mouse's relative social status, competitive ability, social discrimination, and sexuality. These traits are essential elements of the socio-sexual behavior of mice as well as humans. Thus, by identifying phenotypic deviants for complex behaviors we will allow geneticists to map behavioral abnormalities onto specific chromosomes and increase the efficacy of genetically altered mice as models for human behavioral disorders.

Agonistic Behavior↗
PubMed1988

Effects of male social status on reproductive success and on behavior in mice (Mus musculus).

Differences in reproduction as well as in behavior in the presence of females were evaluated according to dominant and subordinate male rank in albino mice, in the temporary absence of each male's antagonist. Dominant males reproduced more successfully than subordinate males. Subordinate males were generally inactive, except for displacement activities, during the first 15 min they were exposed to female partners. These findings suggest that mechanisms other than male-male interference or mating order may be operating or influencing behavior and reproductive results.

Agonistic Behavior↗
PubMed1975

Functional organization of the rat amygdala with respect to avoidance behavior.

Bilateral electrolytic lesions in the periamygdaloid piriform cortex of female albino rats produced marked disruptive effects on the acquisition of active avoidance responses in a 1-way as well as a 2-way test situation, significantly impaired passive avoidance behavior, and inhibited feeding in a novel environment. Lesions in each of the 6 major subdivisions of the amygdala (cortical, medial, central, intercalated, lateral, and basolateral nuclei) consistently produced facilitatory effects on active avoidance behavior in 1-way as 2-way situations. Passive avoidance behavior was impaired in animals with lesions in the central, intercalated, and basolateral nuclei. Damage to the anterior amygdaloid area or the the nuclei of the lateral olfactory tract did not reliably affect active or passive avoidance behavior.

Agonistic Behavior↗
PubMed2006

Molecular analysis of flies selected for aggressive behavior.

Aggressive behavior is pervasive throughout the animal kingdom, and yet very little is known about its molecular underpinnings. To address this problem, we have developed a population-based selection procedure to increase aggression in Drosophila melanogaster. We measured changes in aggressive behavior in the selected subpopulations with a new two-male arena assay. In only ten generations of selection, the aggressive lines became markedly more aggressive than the neutral lines. After 21 generations, the fighting index increased more than 30-fold. Using microarray analysis, we identified genes with differing expression levels in the aggressive and neutral lines as candidates for this strong behavioral selection response. We tested a small set of these genes through mutant analysis and found that one significantly increased fighting frequency. These results suggest that selection for increases in aggression can be used to molecularly dissect this behavior.

Aggression↗
PubMed2001

Situations of violence in the lives of girl gang members.

Women and violence has become a topic of increasing concern. Women's involvement in perpetrating violence, especially girl gang members, also has raised national concern. The participation of young women in gangs and gang violence has caused public consternation as they are perceived to be violating traditional notions of femininity. In spite of this increased concern and burgeoning literature, significant gaps still exist in our understanding of the role of young women in gangs, the nature and extent of female gang members' victimization, and the extent of their involvement in perpetrating violence. The purpose of this paper is to examine the role of violence in the lives of female gang members. The analysis draws from the qualitative and quantitative data of an ongoing comparative study on ethnic youth gangs in the San Francisco Bay Area. The analysis is organized around the situations of violence these young women face from early childhood within the family setting to their current status within the gang and on the streets.

Adaptation, Psychological↗
PubMed2002

The treatment of Tourette's syndrome: current opinions.

Correct education of the patient is one of the most important aspects in the treatment of Tourette's syndrome. Pharmacotherapy is often unsatisfactory and therefore should be limited to those patients who are significantly impaired. Therapy must be individualised and the most troublesome symptom should be targeted first. In the treatment of tics, dopamine receptor blocking agents are currently the most effective drugs. It is currently unknown whether classic neuroleptics, such as pimozide, selective dopamine receptor antagonists, such as sulpiride, or newer atypical antipsychotics, such as risperidone, have the best adverse effect profile. Tiapride can be used as an alternative, particularly in children. Selective serotonin-re-uptake inhibitors are recommended for the treatment of obsessive-compulsive behaviour. In children suffering from attention deficit hyperactivity disorder, psychostimulants, such as methylphenidate, are the treatment of choice. Recent studies have provided increasing evidence that stimulants do not cause a significant increase in tics in the majority of patients.

Adrenergic alpha-Agonists↗
PubMed1994

Compensatory changes in the hippocampus following intradentate infusion of colchicine.

Direct infusion of colchicine into the dentate gyrus of the hippocampus kills granule cells and elicits behavioral, neurochemical and neuroanatomical changes. Colchicine-treated rats are less sensitive to the behavioral effects of cholinergic muscarinic receptor antagonists and more sensitive to cholinergic agonists. These behavioral changes are associated with time- and dose-dependent alterations in the cholinergic signal transduction mechanism. Carbachol-stimulated turnover of phosphoinositides is increased in the hippocampus of colchicine-treated rats; similar changes are not observed in the cortex or striatum of colchicine-treated animals. Intradentate colchicine produces a significant increase in choline- acetyltransferase activity and staining for acetylcholinesterase activity in the hippocampus, suggesting reactive synaptogenesis of cholinergic fibers. Other studies have shown that the integrity of the septohippocampal pathway is necessary for these colchicine-induced compensatory changes to occur. It is suggested that the mechanism for these neurochemical changes in colchicine-treated animals may be occurring via alterations in negative feedback control of receptor-G-protein-mediated phosphoinositide hydrolysis.

Animals↗
PubMed1995

Dopamine receptor supersensitivity.

Dopamine (DA) receptor supersensitivity refers to the phenomenon of an enhanced physiological, behavioral or biochemical response to a DA agonist. Literature related to ontogenetic aspects of this process was reviewed. Neonatal 6-hydroxydopamine (6-OHDA) destruction of rat brain DA neurons produces overt sensitization to D1 agonist-induced oral activity, overt sensitization of some D2 agonist-induced stereotyped behaviors and latent sensitization of D1 agonist-induced locomotor and some stereotyped behaviors. This last process is unmasked by repeated treatments with D1 (homologous "priming") or D2 (heterologous "priming") agonists. A serotonin (5-HT) neurotoxin (5,7-dihydroxytryptamine) and 5-HT2C receptor antagonist (mianserin) attenuate some enhanced behavioral effects of D1 agonists, indicating that 5-HT neurochemical systems influence D1 receptor sensitization. Unlike the relative absence of change in brain D1 receptor number, DA D2 receptor proliferation accompanies D2 sensitization in neonatal 6-OHDA-lesioned rats. Robust D2 receptor supersensitization can also be induced in intact rats by repeated treatments in ontogeny with the D2 agonist quinpirole. In these rats quinpirole treatments produce vertical jumping at 3-5 wk after birth and subsequent enhanced quinpirole-induced antinociception and yawning. The latter is thought to represent D3 receptor sensitization. Except for enhanced D1 agonist-induced expression of c-fos, there are no changes in the receptor or receptor-mediated processes which account for receptor sensitization. Adaptive mechanisms by multiple "in series" neurons with different neurotransmitters may account for the phenomenon known as receptor supersensitivity.

Animals↗
PubMed1995

Dopamine receptor agonist- and antagonist-induced behaviors in primates previously treated with dopamine receptor antagonists: the pathogenetic mechanisms of acute oral dyskinesia.

Eight Cebus apella monkeys previously treated with dopamine D1 and D2 receptor antagonists were used to elucidate the pathophysiology of acute oral dyskinesia. Five monkeys had mild oral tardive dyskinesia because of previous antagonist treatment. Interactions between the dopamine (DA) D1 receptor agonist SKF 81297 and the DA D2/D3 receptor agonist quinpirole, DA D1 and D2 receptor antagonists, and the anticholinergic biperiden were investigated. SKF 81297, 0.3 mg/kg, induced acute oral dyskinesia and grooming, which were each inhibited by the DA D1 receptor antagonist NNC 756 in a dose-dependent manner. The DA D2 receptor antagonist raclopride enhanced SKF 81297-induced acute oral dyskinesia and suppressed SKF 81297-induced grooming, each with bell-shaped dose-effect curves. Quinpirole, 0.1 mg/kg, induced a hyperarousal syndrome (i.e., increased arousal, stereotypy, and locomotion). Concomitant treatment with SKF 81297 and quinpirole caused an extreme hyperarousal syndrome but antagonized acute oral dyskinesia and grooming, suggesting a synergistic effect of high-efficacy DA D1 and D2/D3 receptor agonists regarding the induction of the hyperarousal syndrome and the antagonism of acute oral dyskinesia and grooming. Biperiden, 0.25 mg/kg, antagonized both the SKF 81297-induced and raclopride-induced acute oral dyskinesia. The results suggest that oral dyskinesia and grooming are independent but most often simultaneously occurring behaviors. Grooming is induced by DA D1 receptor agonists and antagonized by D1 and D2 antagonists and D2/D3 agonists. Acute oral dyskinesia is induced by D1 agonists and lower doses of D2 antagonists, but antagonized by D1 antagonists, D2/D3 agonists, and anticholinergics. These results suggest varying interactions between dopaminergic receptor subtypes in different types of dopaminergic behaviors.

Animals↗
PubMed1994

Behavioral activation of neurokinin-1 agonists in relation to enzymatic degradation in the spinal cord.

Intrathecal (i.t.) injection of substance P (SP) induced reciprocal hindlimb scratching directed mainly toward the abdominal regions in mice. This behavior pattern appeared within the first minute after i.t. injection of SP. Similar behavioral effects were produced by i.t. injection of neurokinin (NK)-1 agonists, physalaemin (Phy) and [Sar9,Met(O2)11] SP (Sar-SP). The duration of scratching varied among NK-1 agonists; of the NK-1 agonists used, Phy had the most long-lasting duration of scratching in contrast to SP that had a short duration. The rank order of scratching duration was Phy > Sar-SP > SP. SP was rapidly degraded by the solubilized enzyme extracted from the mouse spinal cord as determined by HPLC. Decay of the scratching response to these NK-1 agonists was parallel with the rate of their degradation by the solubilized enzyme. These results suggest that a relatively long-lasting scratching behavior induced by Phy is mainly attributed to the stability against peptidases in the spinal cord.

Animals↗