EFFECTS OF AROMATIZABLE ANDROGENS ON AGGRESSIVE BEHAVIOUR AMONG RATS (RATTUS NORVEGICUS)

1979 ◽  
Vol 83 (1) ◽  
pp. 17-26 ◽  
Author(s):  
MARJORIE H. CHRISTIE ◽  
R. J. BARFIELD

SUMMARY Three experiments were used to test the applicability of the aromatization hypothesis of androgen action to aggressive behaviour among Norway rats. In Expt 1, administration of testosterone propionate was highly effective in restoring aggressive behaviour to castrated rats while 17β-hydroxy-5α-androstan-3-one was of intermediate effectiveness. Of the steroids tested in Expt 2, androstenedione and testosterone were highly effective, 17β, 19-dihydroxyandrost-4-en-3-one was of intermediate effectiveness and cholesterol was ineffective. The results of Expt 3 indicated that treatment with testosterone or oestradiol both resulted in increased aggression while treatment with (5α, 17β)-17, 19-bis(acetyloxy)-andostan-3-one diacetate (5α-19-hydroxytestosterone) was without effect. Androgens which were aromatizable and could be 5α reduced, i.e. testosterone, testosterone propionate and androstenedione, were highly effective in restoring aggressive behaviour; however, two other steroids, 5α, 19-hydroxytestosterone which is 5α reduced, and 19-hydroxytestosterone, which can be aromatized, were respectively of low or medium effectiveness on behaviour. However, oestradiol, which did not maintain sexual development of accessory glands, was highly effective in the restoration of aggressive behaviour. Since the behaviourally active steroids in the present experiments were not only those predicted by the aromatization hypothesis, it is proposed that several steroids are capable of activating aggressive behaviour and that the aromatization hypothesis does not adequately explain the hormonal basis of aggressive behaviour among Norway rats.

1986 ◽  
Vol 96 (3) ◽  
pp. 467-473 ◽  
Author(s):  
A. P. Buckle

SUMMARYThe anticoagulant rodenticide flocoumafen was tested against warfarin-resistant Norway rats (Rattus norvegicus Berk.) infesting farm buildings. Complete control was obtained in 10–21 days (mean 14·2 days) in six treatments in which baits poisoned with 0·005% flocoumafen were maintained, in surplus, until rats ceased to feed from them. A further six treatments, in which the application of poisoned bait was restricted to periodic placements of 50 g, were also completely successful in 15–30 days (mean 21·0 days). Less poisoned bait was used in the restricted flocoumafen treatments than in the unrestricted treatments but the time taken to control the rat infestations was significantly longer.


2021 ◽  
Vol 10 (1) ◽  
pp. 45-47
Author(s):  
Anil Kumar Sah ◽  
Bipin Maharjan ◽  
Mahesh Bahadur Adhikari ◽  
Suman Baral ◽  
Mimi Giri

Disorder of Sexual Development (DSD) is a group of congenital conditions with atypical development of sex at chromosomal, gonadal or anatomic level. Genetic males with DSD (46 XY DSD) can present with female external genital phenotype, ambiguous, or a micropenis. It is caused by incomplete intrauterine masculinization with or without the presence of Müllerian structures. It results either from decreased synthesis of testosterone or DHT or from impairment of androgen action. Herein, we report a case of a 13-year child raised as female with hoarseness of voice and gradual enlargement of clitoris with hormonal assessment not suggestive of either 5 Alfa Reductase deficiency, Congenital Adrenal Insufficiency Syndrome or 17β-Hydroxysteroid Dehydrogenase deficiency


1963 ◽  
Vol 41 (1) ◽  
pp. 1147-1153
Author(s):  
J. S. Willmer ◽  
O. Héroux

The in vitro adrenal steroid secretion of wild Norway rats (Rattus norvegicus) captured during the winter differed in quantity, but not in quality, from that of similar rats captured during the summer. Whereas there was no evident seasonal effect on adrenal weight either in males or in females, adrenals of both sexes secreted at a faster rate during the winter than during the summer, this increase involving the four groups of steroids characterized chromatographically during both seasons and in both sexes; the predominant steroid secreted was corticosterone. This seasonal adjustment in adrenal activity is similar to that observed in white rats kept in group cages exposed outdoors to the natural summer and winter environmental conditions, but it differs from that found in white rats cold-acclimated in the laboratory, in which adrenal activity is lower than normal after cold acclimation.


2003 ◽  
Vol 30 (2) ◽  
pp. 187 ◽  
Author(s):  
Sophie Rouys ◽  
Jörn Theuerkauf

We studied the distribution of introduced mammals in six nature reserves of New Caledonia's southern province. Polynesian rats (Rattus exulans) were common in both rainforest and shrubland but their abundance decreased with increasing altitude. Ship rats (Rattus rattus) were abundant in rainforest but less numerous in shrubland and their abundance did not increase with altitude. We found no Norway rats (Rattus norvegicus) or house mice (Mus musculus domesticus) in reserves. Feral pigs (Sus scrofa) used mainly rainforest but also shrubland and preferred foraging in valleys with alluvial soils. Rusa deer (Cervus timorensis) selected shrubland over rainforest. Feral cats (Felis catus) were widely distributed in the reserves, whereas dogs (Canis familiaris) strayed into reserves but did not form feral populations.


1965 ◽  
Vol 49 (2) ◽  
pp. 193-206 ◽  
Author(s):  
Fred A. Kind ◽  
A. Folch Pi ◽  
M. Maqueo ◽  
L. Herrera Lasso ◽  
A. Oriol ◽  
...  

ABSTRACT The effect of various steroids injected into 5 day old male and female rats was evaluated at the age of 45 days. In the males the degree in which testes and accessory sex tissues were atrophied, and in the females the degree of inhibition of luteinization were the indices. Various synthetic oestrogens were potent inhibitors of sexual development in both sexes while androgens were less active. The activity of several oestrogens in this test does not correlate with oestrogenic potency as measured in the uterotrophic test. Testosterone propionate produced moderate atrophy of testes and accessory sex tissue but spermatogenesis was not impaired.


2020 ◽  
Vol 287 (1939) ◽  
pp. 20202327
Author(s):  
Nina Gerber ◽  
Manon K. Schweinfurth ◽  
Michael Taborsky

Reciprocity can explain cooperative behaviour among non-kin, where individuals help others depending on their experience in previous interactions. Norway rats ( Rattus norvegicus ) cooperate reciprocally according to direct and generalized reciprocity. In a sequence of four consecutive experiments, we show that odour cues from a cooperating conspecific are sufficient to induce the altruistic help of rats in a food-exchange task. When rats were enabled to help a non-cooperative partner while receiving olfactory information from a rat helping a conspecific in a different room, they helped their non-cooperative partner as if it was a cooperative one. We further show that the cues inducing altruistic behaviour are released during the act of cooperation and do not depend on the identity of the cue provider. Remarkably, olfactory cues seem to be more important for cooperation decisions than experiencing a cooperative act per se . This suggests that rats may signal their cooperation propensity to social partners, which increases their chances to receive help in return.


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