Stimuli for male mouse (Mus musculus) ultrasonic courtship vocalizations: Presence of female chemosignals and/or absence of male chemosignals.

In research on animal chemocommunication, biological odors are sometimes presented by being applied to a "neutral" animal (e.g., castrated or ovariectomized conspecific). This technique is typically utilized when the behavioral response to the odor requires the presence of a conspecific. In 5 experiments, DBA/2J and 2 F? hybrid strains of mice that might be expected to be neutral stimuli were examined for their abilities to elicit ultrasonic courtship vocalizations from male mice. Paradoxically, adult castrated males, adult males that were neonatally castrated, hypophysectomized males, prepubertal females, and hypophysectomized females all elicited more vocalizations than would have been predicted from previous research in which their urine alone was used as the stimulus. These and previous results are consistent with courtship vocalizations being promoted by chemosignals from females and/or by an absence of cues from males. Thus, a truly neutral conspecific for presenting female sex odors may not exist in mice. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sexual dimorphism in ultrasonic vocalizations of mice (Mus musculus): Gonadal hormone regulation.

Male mice, during courtship and sexual behavior, vocalize substantially more 70-kHz ultrasounds than do females. Four experiments conducted with 109 male and female DBA/2J and ADK2F? mice demonstrated that testosterone propionate (TP) substantially increased ultrasonic emissions and mounting by ovariectomized females and that long-term gonadectomized males and females increased their amount of ultrasound production in response to TP to approximately the same levels. From these results it is suggested that the sexual dimorphism normally seen in ultrasonic vocalizations can be accounted for by the activational effects of androgen in adulthood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ultrasonic vocalizations by male house mice (Mus musculus) to novel odors: Roles of infant and adult experience.

Conducted 2 experiments to examine 70-kHz ultrasonic courtship vocalizations by adult male mice to novel odors following exposure to these odors in infancy and/or adulthood. Exp I, with 72 males, demonstrated that adult males normally do not vocalize to the urine of female rats but would if adult female mice odorized with female rat urine were repeatedly encountered postpubertally. On the other hand, encountering their own mother odorized with female rat urine from birth until weaning did not promote vocalizations to the urine of female rats. Exp II, with 100 males, examined vocalizations to the urine of female mice whose urinary odor was altered by the ingestion of fenugreek, a spice. Greater amounts of vocalization again were seen by males that as adults encountered females that had ingested fenugreek. Again, experience with the novel odor during infancy was not associated with elevated vocalizations during adulthood either to fenugreek-altered urine or to the fenugreek odor itself. Vocalizations to 2 different novel odors occurred only after an adult male had encountered an adult female odorized with the novel odor. (57 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alcohol withdrawal severity in inbred mouse (Mus musculus) strains.

Male mice (Mus musculus) from 15 standard inbred strains were exposed to a nearly constant concentration of ethanol (EtOH) vapor for 72 hr, averaging 1.59 ± 0.03 mg EtOH/mL blood at withdrawal. EtOH- and air-exposed groups were tested hourly for handling-induced convulsions for 10 hr and at Hours 24 and 25. Strains differed markedly in the severity of withdrawal (after subtraction of control values), and by design these differences were independent of strain differences in EtOH metabolism. Correlation of strain mean withdrawal severity with other responses to EtOH supported previously reported genetic relationships of high EtOH withdrawal with low drinking, high conditioned taste aversion, low tolerance to EtOH-induced hypothermia, and high stimulated activity after low-dose EtOH. Also supported were the positive genetic correlations among EtOH, barbiturate, and benzodiazepine withdrawal. Sensitivity of naive mice to several chemical convulsant-induced seizures was also correlated with EtOH withdrawal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Urinary chemosignals from mice (Mus musculus): Acceleration and delay of puberty in related and unrelated young females.

Conducted 5 experiments (N?=?576) to determine the possible differential effects that urinary chemosignals from genetically related and unrelated donors have on puberty onset in female mice. The 1st 4 experiments (n?=?495), with a laboratory mouse strain, demonstrated no differential acceleration or delay of sexual maturation, with respect to a close genetic relation between donors and recipients, due to the chemosignals from estrous, diestrous, pregnant, or lactating females or grouped females. In the last experiment, wild stock Mus were used; all of the results were comparable to those found in laboratory stocks. There were no instances of differential acceleration or delay based on close genetic relatedness of donors and recipients. Results conform with a general hypothesis that the urinary chemosignals in mice communicate information about the adequacy of reproductive conditions to conspecifics. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Of mice (Mus musculus) and toddlers (Homo sapiens): Evidence for species-general spatial reorientation.

There is ongoing debate in spatial cognition about the mechanisms by which organisms are able to reorient, or reestablish a position, in the world after losing their bearing. The traditional view is that there is an encapsulated reorientation module that can only process environmental geometry such as distances or angles (Cheng, 1986). Recently, this view has been challenged on the grounds that the reorientation mechanism is only able to accept geometric information and may instead depend on a more general ability to use relative cues. J. Huttenlocher and S. F. Lourenco (2007) demonstrated that toddlers are successfully able to reorient with continuous cues but show remarkable deficits using categorical cues that are similar in perceptual complexity for reorientation. Here, the authors show the same pattern of results with mice (Mus musculus). These findings provide evidence that there is a homologous reorientation mechanism between mice and humans. Thus, future researchers can examine the genetic basis of this important cognitive ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Olfactory discrimination of mouse strains (Mus musculus) and major histocompatibility types by humans (Homo sapiens).

Examined, in 5 experiments, whether the olfactory differences apparent to mice are also accessible to humans, using a total of 63 human Ss. In Exp I, Ss were asked to distinguish between the whole-body odors of live mice differing genetically only at the major histocompatibility gene complex (H-2). In Exps II and III, the odor source was mouse fecal pellets, and in Exps IV and V, the odor source was mouse urine. Results reveal that humans can use olfaction to discriminate closely related strains of mice. The possibility that excreted metabolites with characteristic odors may have predated the evolution of an adaptive function for these odors in social communication is suggested. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibition of infanticide and onset of paternal care in male mice (Mus musculus).

In 7 experiments, using 331 male mice, unmated males tended to be infanticidal toward test pups. However, between mating and the birth of their litter, males stopped killing and became paternal toward test pups. Both the act of copulation and postmating cohabitation with the female influenced this onset of paternal care. The magnitude of the effect of copulation was markedly influenced by prior social experiences. However, just 1 day of cohabitation after mating had the effect of reducing infanticidal tendencies and increasing paternal responses. The timing of this effect coincided with changes in the agonistic interactions between the sexes and apparent changes in dominance/subordinancy relations. The overall effect was a complete inhibition of infanticide that allowed the onset of paternal care. Findings are discussed in relation to those of a previous study by the present author and M. C. Ostermeyer (see record 1985-00491-001), particularly with regard to the hypothesis that the reduction in infanticide may reflect subordination of males to females after mating. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ultrasonic vocalizing by adult female mice (Mus musculus).

Conducted 5 experiments, using 1,029 female and 805 male mice, to examine adult female mouse ultrasound emission. Results indicate female ultrasonic vocalizing to be (a) typically displayed among female mouse dyads and (b) comparable to the ultrasonic vocalizing levels obtained among male–female pairs. Genotypically based variations in the production of ultrasounds by females were also noted. Like males, socially naive females readily ultrasonically vocalized to anesthetized female conspecifics and rarely vocalized to anesthetized males. Unlike males, socially experienced females emitted few ultrasounds to either female urine or female-soiled cage shavings. Although social experience increased the ultrasound emission of males to female sex cues, the production of ultrasounds by females to these cues was decreased by social experience. Implications with regard to the existence of a behavioral/functional sexual dimorphism in adult mouse ultrasonic vocalizing are discussed. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Litter gender composition affects maternal behavior of the primiparous mouse dam (Mus musculus).

Thirty-nine litters of the outbred Swiss CD-1 mouse strain were reduced at birth to 6 pups, according to three conditions MM (all males), MF (3 males and 3 females), or FF (all females). The maternal behavior of their respective dams (frequency and duration of nursing, licking, nestbuilding, and other activities such as eating, drinking, sniffing, grooming, and undirected locomotor activity) were scored during a single 10-min session on Days 2, 3, 5, 7, 10, 14, and 18. Dams rearing MM litters showed higher scores of maternal care on Days 2 and 18 in the case of nursing, on Days 2, 7, and 10 in the case of nest-building, and on Day 18 in the case of licking. These results confirm previous rat data, which indicated that male and female pups are exposed early in infancy to a different pattern of maternal behavior. Concomitant measurements of pup development (body-weight gain and achievement of a number of physiological and neurobehavioral landmarks) indicated that these effects of litter gender composition are not mediated by gross changes in the maturational trends of the pups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Task-dependent genetic influences on behavioral response of mice (Mus musculus) to acetaldehyde.

Employed acetaldehyde as a pharmacological agent in behavioral tests designed to assess genetic influences on response to the drug. When used as a poison in a conditioned taste aversion study with 200 male mice, acetaldehyde was more effective at inducing aversions in DBA/2J mice than in C57BL/6J mice. In another experiment, however, 6 C57 mice were more affected than were 6 DBA mice by acetaldehyde effects on loss of righting reflex. Implications for postulated genetic control of ethanol preference and neurosensitivity are discussed. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Male acceleration of puberty in female mice (Mus musculus).

Nine experiments investigated various aspects of the acceleration of puberty in female ICR/Alb house mice (N?=?754) produced by the presence of a male mouse or urine from males. Grouping males had no effect on the urinary chemosignal that accelerates puberty, except that urine from dominant males produced greater acceleration than urine from subordinates. Young female mice must be exposed to the male urine for at least 2–3 hrs/day or to the presence of a male for 1 hr/day to produce acceleration of first vaginal estrus. Females were accelerated to the same extent in attaining puberty whether treated with urine from the same male or a different male each day. Urine from the father or a full brother, or the presence of those close relatives, exerted no differential acceleratory or retarding effect on puberty when compared with urine from or the presence of unrelated males. Excreted or bladder urine from adrenalectomized males accelerated puberty to the same extent as urine from intact males, but the presence of an adrenalectomized male did not produce the same degree of acceleration as when an intact male was present. Behavioral observations indicate that adrenalectomized males pursued young females less and attempted fewer mounts during a brief test period. Implications are noted for the understanding of both the mechanisms of acceleration of puberty in the house mouse and the population and reproductive biology of these mice. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maternal performance of inbred and hybrid laboratory mice (Mus musculus).

60 primiparous mice from 3 inbred strains (A/J, DBA/2J, C57BL/6J) and their reciprocal crosses were subjected to various tests of maternal behavior. During pregnancy, S was placed in a seminaturalistic environment, and her nest-building activity was assessed. Following parturition, S's retrieval behavior was measured under conditions that placed conflicting demands on her behavioral repertoire. Results indicate that there were both qualitative and quantitative differences between inbred and hybrid Ss. Prenatal nest-building activity showed heterosis on various measures of relevant environmental manipulations. The retrieval data suggest that inbred Ss were less able to integrate their behavior into a coherent pattern. The level of inbreeding of the pups had no significant effect on the aspects of maternal behavior measured. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Male mouse (Mus musculus) attraction to airborne urinary odors of conspecifics and to food odors: Effects of food deprivation.

Five experiments demonstrated that 112 male mice were strongly attracted to the urinary odors of females, and that male urinary odors were considerably less attractive. The strong attraction to female urinary odors did not require that the males have postweaning experience with females. Males with continuous access to food and water were much more strongly attracted to female urinary odors than to the airborne food odors. Female urinary odors remained more attractive than food odors after 24-hr food deprivation, and only after 48-hr deprivation did the attractiveness of food odors approximate that of female urine. Although 48-hr food deprivation appeared to equalize the attractiveness of urinary and food odors, this regimen did so not by diminishing the attractiveness of female urine but rather by increasing the attractiveness of food odors. It is argued that the attraction that male mice exhibited to female urinary odors in this odor-testing apparatus reflected, at least in part, a biologically important precopulatory communication system. (29 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bitter avoidance in guinea pigs (Cavia porcellus) and mice (Mus musculus and Peromyscus leucopus).

Rejection of bitter substances is common in many species and may function to protect an animal from ingestion of bitter-tasting toxins. Since many plants are bitter, it has been proposed that high tolerance for bitterness would be adaptive for herbivores. Earlier studies conducted on herbivorous guinea pigs (Cavia porcellus) have been used to support this proposal. We tested guinea pigs with bitter plant secondary metabolites (salicin, caffeine, quinine hydrochloride) and bitter protein hydrolysates (two types of hydrolyzed casein, hydrolyzed soy) in a series of two-choice preference tests. For comparison, we tested two nonherbivorous mouse species (Mus musculus and Peromyscus leucopus). Guinea pigs did show weaker avoidance of quinine hydrochloride than did the mice, confirming predictions generated from earlier work. However, guinea pigs had similar responses to caffeine as did Peromyscus. Both of these species showed weaker avoidance responses than Mus to 10 mM caffeine. For salicin, guinea pigs were the only species to avoid it at 10 mM and their preference scores at this concentration were significantly lower than for the two mice species. Guinea pigs avoided all of the protein hydrolysates more strongly than the other species. Responses to the protein hydrolysates did not reflect the patterns observed with the simple bitter compounds, suggesting that other properties of these complex stimuli may be responsible for guinea pig avoidance of them. Our results suggest caution in accepting, without further empirical support, the premise that guinea pigs (and herbivores in general) have a generalized reduced bitter sensitivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characteristics of thirst and sodium appetite in mice (Mus musculus).

Intakes of water and NaCl solution were examined in mice following treatment with agents that stimulate or mimic components of the renin-angiotensin-aldosterone system. Injections of angiotensin II or isoproterenol produced little water intake compared with robust responses to either intracellular dehydration or extracellular dehydration induced by treatment with polyethylene glycol. In studies on appetite for NaCl solution, mice exhibited no spontaneous preference for NaCl solution over water and did not change this preference during treatment with deoxycorticosterone acetate, a sodium-deficient diet, or after adrenalectomy. Plasma concentrations of aldosterone were increased in intact mice fed a sodium-deficient diet but not eliminated by adrenalectomy. Acute treatment with furosemide in combination with a sodium-deficient diet stimulated an appetite for NaCl solution. Chronic oral administration of an angiotensin I converting enzyme inhibitor failed to induce a NaCl appetite. Findings show that mice are refractory to the induction of water or NaCl intake by stimuli of the renin-angiotensin-aldosterone system, highly effective in rats, suggesting that there may be major differences among rodents in hormonal determinants of behaviors related to hydromineral homeostasis. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Interactions of contact, odor cues, and androgens in strange-male-induced early pregnancy disruptions in mice (Mus musculus).

Novel males can disrupt early pregnancy in female house mice (Mus musculus). In Experiment 1, exposure to novel males disrupted pregnancy, but exposure to male urine did not. In Experiment 2, urine from male or female mice or rats painted on females' noses did not influence pregnancy. In Experiment 3, the conjunction of urine painted on female's noses and vulval stimulation did not affect pregnancy more than water with similar stimulation. In Experiment 4, males housed above females were separated from them by a wire mesh grid; intact males disrupted pregnancy, but castrated ones did not. In Experiment 5, such housing of castrated males or ovariectomized females produced a strong disruption of pregnancy if the stimulus animal was given testosterone but not if it was given oil injections. In Experiment 6, transfers of odorous emissions failed to disrupt pregnancy. Contact and androgen activity are necessary for strange males to disrupt pregnancy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic influences on digging behaviors in mice (Mus musculus) in laboratory and seminatural settings.

Examined digging behaviors of several inbred strains of laboratory mice and some of their crosses in 3 contexts. In laboratory burrow boxes, C57BL/6Abg mice constructed more sophisticated burrow systems than did BALB/cAbg mice. Their F? hybrids built burrow systems more complex than either parental strain. The same pattern of genetic influence was observed in an outdoor pen. In an escape task that required digging, BALB/c mice escaped more quickly than did C57BL/6 mice; their F? hybrids showed dominance toward the BALB/c phenotype. Results indicate that behavioral polymorphisms in digging behavior, which may relate to habitat selection, have a genetic basis. The dominance and overdominance toward the better digging parental strain in each type of task suggest the possible evolutionary importance of these digging behaviors. (18 ref) ?55 (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral development and strain differences in perinatal mice (Mus musculus).

Examined the perinatal development of spontaneous body movements and reflexes in Slc:ICR, C3H/He, and BALB/c mice. Mice were observed from Day 18 (a day before normal parturition) to Day 21.5 of gestation. The developmental changes of spontaneous body movements and reflexes occurred quickly. Strain differences in behavioral development were detected in the duration of spontaneous body movements but not in the occurrence of reflexes. Hybrid mice were more active than their parental strains with regard to duration of spontaneous body movements. The rooting reflex and crossed extensor reflex in hybrid mice occurred more frequently on Day 18 than in their parental strains. These results indicate that the perinatal period is characterized by quick qualitative and quantitative changes in behavioral development and by the appearance of these genetic differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)