Effects of olfactory bulb ablation and androgen on marking and agonistic behavior in male Mongolian gerbils (Meriones unguiculatus).

Male Mongolian gerbils, selected for high marking frequency, were paired with male opponents, and marking and fighting behavior were recorded. Animals then underwent castration, bilateral bulbectomy, unilateral bulbectomy, the combined operations, or a sham operation; and their behavior was again observed. All operated animals showed drastic reduction in both marking and aggressive encounters. Injections of testosterone propionate (TP) produced complete restoration of marking in castrates, but not in bilaterally or unilaterally bulbectomized animals or combined operates. The exhibition of aggression after injections of TP, however, was enhanced to supernormal levels in bulbectomized or bulbectomized-castrated animals. The results suggest the following: that removal of the olfactory bulbs may eliminate a critical neural input necessary for the normal expression of marking and agonistic behavior; that although marking and fighting are influenced by olfactory input and gonadal steroids, their regulatory mechanisms may not be identical; and that removal of the bulbs may sensitize a neural mechanism controlling aggression, thus potentiating its elicitation following administration of exogenous androgen. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of antidepressant drugs on the behavior of olfactory bulbectomized and sham-operated rats.

Examined the reversal of the olfactory bulb lesion deficits in 12 sham or bulbectomized male Sprague-Dawley rats following chronic antidepressant drug administration (mianserin HCl, 10 mg/kg; tranylcypromine sulfate, 10 mg/kg; and iprindole HCl, 10 mg/kg). Findings indicate that this reversal was not due to molecules of the drug per se but rather to some drug-induced change in the neuronal substrate that continued for at least 5 days after the last dose of drug. These endocrine, behavioral, and pharmacological similarities suggest that the study of rats with olfactory bulb ablation may make significant contributions to the understanding of the neuroscience of primary unipolar depression in humans. (45 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estrogen facilitation of progesterone-induced incubation behavior in castrated male ring doves.

Previous studies have shown that incubation is shared by both male and female ring doves and is induced, without prior participation in courtship and nest building, by progesterone (100 mg/day) treatment. In the present experiment with 52 mature male ring doves, it was shown that the effectiveness of progesterone is markedly reduced by castration and restored after estradiol benzoate (200 mg/day * 14) pretreatment, thus simulating the endocrine events which precede incubation in the female. Estrogen also stimulated the appearance of nest cooing (another isomorphic behavior) but not bow cooing (a male-specific display). Results are discussed in terms of hormonal specificity underlying reproductive behavior and the possible physiological roles of estrogen and progesterone in the ring dove. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hormonal regulation of adult partner perference behavior in neonatally ATD-treated male rats.

Male rats, neonatally treated with ATD (1,4,6-androstatriene-3,17-dione), which blocks the aromatization of testosterone into estradiol (E?), were tested for adult partner preference behavior (PPB; estrous female vs active male). Castration caused a decrease in preference for the female partner in all males, with ATD males showing lower preference for the female partner than controls. Long-term castrated males did not show preference for either partner. Precastration levels of PPB in control males occurred after treatment with E? or dihydrotestosterone (DHT) plus E?. DHT alone had no effect on PPB. With E? alone, the ATD males clearly preferred the male partner. When DHT was added, these ATD males showed no preference for either partner or a low preference for the female partner. In conclusion, adult PPB in male rats is activated by endogenous testosterone or by both its metabolites (DHT and E?) or by E? alone. ATD males showed a much lower preference for the female. There was a differential effect of DHT and E?: DHT had no effect, but E? clearly caused ATD to prefer the male partner and control males to prefer the female partner. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of assertion training on aggressive behavior of adolescents.

The effects of assertion training on aggressive adolescents' behavior were examined. 30 9th-grade students judged by peers to be aggressive were randomly assigned to assertion training, placebo, and no-treatment control groups. The experimental group received 8 50-min assertion training sessions, and the 2 other groups received either no contact or placebo sessions concerning decision-making. Results show that the assertion training yielded significant improvement on the assertion scale, but it had little effect on peer-judged aggression. The implications of the findings are discussed. (6 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bisexual behavior in male rats treated neonatally with antibodies to luteinizing hormone-releasing hormone.

Investigated in 3 experiments, the possibility that luteinizing hormone-releasing hormone (LHRH) is involved in the process of sexual differentiation by injecting 163 male Wistar rat pups on Days 1 and 3 of life with specific antibodies to LHRH (AB-LHRH) or with normal rabbit serum. At maturity, Ss treated with AB-LHRH were as fertile as controls and their mount and intromission latencies and the postejaculatory interval were extended only slightly. However, they showed high levels of lordotic behavior, including ear wiggling, when castrated and primed with estrogen or with estrogen plus progesterone. Testosterone propionate, administered neonatally together with AB-LHRH, did not reverse these effects. Ss treated with AB-LHRH and castrated as adults did not respond to estrogen priming by releasing a surge of luteinizing hormone, a result indicating that they did not possess the female type of gonadotropin regulation. Findings indicate that neutralization of endogenous LHRH during neonatal life selectively blocked defeminization of behavior without affecting the process of masculinization. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decline of sexual behavior in castrated male rats: effects of female precopulatory behavior

Ventricle cells from neonatal rats were cultured in a medium preventing cell proliferation on a modified Roller apparatus with a defined pericellular oxygen partial pressure (pO2) of 38 or 0.6 mm Hg for about one week. The cells were harvested after the second and eighth day of culture (corresponding to one or seven days of culture under a defined pO2) and prepared for electron microscopy. Electron micrographs of this material were examined by stereologic techniques. The obtained results showed some deviations of mitochondrial fine structure of heart muscle cells depending on oxygen supply. During cultivation with a pO2 of 0.6 mm Hg (hypoxic conditions) we observed a proportional increase in mitochondria without cristae and an increase in size accompanied by a more irregular shape. On the contrary, the mitochondria of cells cultured with a pericellular pO2 of 28 mm Hg, which we consider to be a normoxic condition, did not show any deviation of inner membrane arrangement, but an increase in number and a decrease of size during cultivation was apparent. The mitochondria-myofibrils ratio decreased during cultivation in both conditions of oxygen supply. The ratio between sarcoplasmatic reticulum and myofibrils decreased markedly at a pO2 of 0.6 mm Hg.     

Gonadal androgen and sociosexual behavior of male mammals: A comparative analysis.

A review of the literature indicates that sexual, aggressive, and scent-marking behavioral patterns are altered by withdrawal and replacement of gonadal androgen in some mammalian species. Although in some animals peripheral organs related to the expression of these behavioral patterns may be affected by androgen, most behavioral influences are caused by the effects of androgen on the central nervous system. Earlier experimental work dealing with species differences in androgen control of sexual behavior suggested that androgen influence was inversely proportional to the relative development of the neocortex. Although this "evolutionary" principle may play a role in the overall picture, recent work reveals that understanding species differences requires an analysis of factors that relate to the responsiveness of the neural tissue in areas of the central nervous system that are affected by androgen. (130 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Responses of male Mongolian gerbils to male gerbil odors.

Offered adult male Mongolian gerbils (Meriones unguiculatus). the opportunity to enter and investigate several combinations of male gerbil-inhabited and uninhabited areas in a 2-choice preference apparatus. Responses of 12 normal, 10 bulbectomized, 10 enucleated, and 9 castrated Ss indicate that: (a) males prefer to investigate areas containing self-generated or conspecific-generated biological odors over areas containing no gerbil odors; (b) although entry and investigation time scores probably reflect different aspects of orientation to biological odors, both measures suggest that the complex of odors generated by males is attractive to male conspecifics; (c) the odors mediating preferences are dependent primarily but not exclusively on testicular androgen; and (d) preference for normal conspecific odors is not dependent on circulating testicular androgen in the responding S. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exogenous androgen activates female behavior in noncopulating, prenatally stressed male rats.

Male copulatory behavior was severely impaired in 39 male offspring of Sprague-Dawley female rats stressed during pregnancy. This deficiency persisted even after castration and prolonged treatment with testosterone propionate and after exposure to electric skin shock. However, androgen treatment effectively activated female lordotic behavior in a large percentage of prenatally stressed males but not in any controls and in only a negligible number of postnatally stressed males. Although prenatal stress demasculinizes and feminizes behavior, no modifications of reproductive morphology were detectable. It is suggested that prenatal stress alters normal sexual behavior differentiation by attenuating testosterone secretion from the fetal testes. (45 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of aggressive cartoons on children's aggressive play.

"The purpose of this study was to test the hypothesis that exposure to aggressive fantasy in an animated cartoon may intensify children's impulses to aggression. Subjects were 36 first grade children, 18 girls and 18 boys, of middle class origin. The intensity of the child's aggressive impulses were inferred from his responses to questions concerning desire to 'play with' or 'pop' a large yellow balloon held by a tester. The experimental findings clearly supported the major prediction." From Psyc Abstracts 36:04:4FF61M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mammalian scent gland marking and social behavior.

Scent-marking behavior is a common method of olfactory communication among mammalian species. The present article reviews concepts of scent marking and presents naturalistic and laboratory illustrations of intraspecific communication. The most informative data and comparative possibilities exist for the following species: ground squirrel, Mongolian gerbil, golden hamster, guinea pig, pika, sugar glider, European rabbit, pronghorn antelope, blacktail deer, Maxwell duiker, lemur monkey, and marmoset monkey. The review points out generalities and differences among these species and suggests how the laboratory and measurement skills of behaviorists and other biologists can be used in this area of research. (41/2 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of the effects of stanozolol, oxymetholone, and testosterone cypionate on the sexual behavior of castrated male rats.

In 3 experiments, adult male Long-Evans rats were castrated and treated daily with an anabolic-androgenic steroid (AAS) compound (either stanozolol, oxymetholone, or testosterone cypionate) for 6 weeks. Subjects were assigned to 5 groups that received injections of a high, medium, or low dose of the AAS, testosterone propionate, or the oil vehicle. Stanozolol failed to maintain ejaculation at any dose tested. Although some subjects receiving the low dose of oxymetholone ejaculated, oxymetholone generally failed to stimulate ejaculation above the levels of the oil group. Testosterone cypionate sustained ejaculation at all doses tested. The relative potency of the medium dose of each AAS in the sex accessory tissues was (from most potent to least potent): testosterone cypionate?>?stanozolol?=?oxymetholone?=?oil. Thus, these 3 AAS compounds produced a range of behavioral and endocrine responses in castrated male rats. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of alcohol on elevated aggressive behavior in male transgenic TGF alpha mice

A simple method using ion-pair high-performance liquid chromatography was established for the rapid and precise simultaneous determination of honokiol (3', 5-di-2-propenyl-1, 1'-biphenyl-2,4'-diol) and magnolol (5,5'-di-2-propenyl-1,1'-biphenyl-2,2'-diol) in oriental pharmaceutical decoctions containing Magnolia bark. An ODS column and a mixture of water involving 10 mM tetra-n-amylammonium bromide (TAA) and acetonitrile (4:6) as a mobile phase were used for the separation. Honokiol and magnolol were eluted without interference of other co-existing components within 12 min.     

Impact of distressed and aggressive behavior.

Two studies examined the hypothesis that distressed behavior induces negative emotions in others but also prompts solicitousness and deters aggression. In Study 1, 48 marital dyads rated various behaviors in terms of their feelings and reactions toward a spouse engaging in each behavior. Distressed behavior prompted both negative and solicitous emotions, but deterred hostile reactions. Aggressive behavior prompted negative feelings and hostile and argumentative reactions. In Study 2, 41 couples rated videotaped examples of a woman engaging in distressed, aggressive, or neutral behavior, with variations in verbal content and nonverbal affect. Examples of distressed behavior prompted more negative feelings and more solicitous feelings than neutral behavior. Aggressive examples prompted more negative feelings and hostile reactions. The studies indicate the importance of distinguishing between distressed and aggressive behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of gonadectomy in infancy and adulthood on handedness in male and female Mongolian gerbils

When assuming a species-typical tripodal posture, female Mongolian gerbils most often rest on their left forepaws and hold their right forelimbs aloft; male gerbils most often do the reverse. This experiment examined effects of gonadectomy, both in infancy and in adulthood, on the sexually dimorphic asymmetry in forelimb use by Mongolian gerbils when maintaining a tripodal stance. In adulthood, both male and female gerbils that had been gonadectomized at birth reversed their forelimb use while in a tripodal stance: Gonadectomized males used their forelimbs as did sham-operated females, and gonadectomized females used their forelimbs as did sham-operated males. Gonadectomy in adulthood abolished the sexual dimorphism in forelimb use seen in sham-operated subjects. It was concluded that gonadal hormones have organizational as well as possible activational effects on adult patterns of forelimb use by gerbils.     

An ethological analysis of nonverbal inhibitors of aggressive behavior in male elementary school children.

Tested the hypothesis that a child's displays of human submission involving diminished body stature have a higher probability of terminating attack by an aggressor than other behaviors exhibited by the child during an agonistic encounter. Groups of 28–34 8–12 yr old male elementary school students were observed in 24 40-min sessions over a 6-wk period. A videotape unit was activated whenever the initiation of agonistic interaction was observed. Results indicate that behaviors involving a diminution of body stature (kneeling, bowing, shoe tying) were found to precede the cessation of agonistic activity between the students significantly more frequently than other forms of behavior exhibited by the student under attack (e.g., threat displays, face-to-face interaction). It is suggested that to the extent that the aggressive encounters of children during play activity represent at least one form of human agonistic activity, a constellation of behaviors exist which serve an appeasement function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of noise and perceived control on ongoing and subsequent aggressive behavior

Two experiments examined the effects of high-intensity (95 dB [A]) noise on ongoing and postnoise aggressive behavior. In Experiment 1, subjects were angered or treated in a neutral manner and given an opportunity to aggress against another subject while being exposed to high-intensity (95 dB) or low-intensity (55 dB) noise. Results indicated that high-intensity noise facilitated aggression for previously angered individuals. Experiment 2 examined postnoise aggression in which subjects completed a math task under high-intensity noise with or without perceived control over the noise. In comparison to a no-noise control, it was found that angered subjects with no control revealed an increase in aggression, whereas perceived-control subjects were no different from no-noise subjects. Results are discussed in terms of the recent Glass and Singer work on noise and task performance and the effects of perceived control on mediating the effects of stressful conditions.