Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Peromyscus”

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 145 records · Page 8Linked to original sources
PubMed1987

Sex differences in magnetic field inhibition of morphine-induced responses of wild deer mice, Peromyscus maniculatus triangularis.

An exposure for 60 min to a 0.5 Hz weak rotating magnetic field (1.5-90 G) reduced the day-time locomotory and analgesic effects of morphine (10 mg/kg) in a wild population of deer mice. Peromyscus maniculatus triangularis. Females displayed significantly lower levels of morphine-induced responses and sensitivity to the inhibitory effects of the magnetic fields than did the males. These responses indicate that there are sex differences in the effects of weak magnetic fields on the opiate-mediated responses of a wild rodent, with males being more responsive to the magnetic stimuli than females.

Analgesia↗
PubMed1988

Male scent-induced analgesia in the deer mouse, Peromyscus maniculatus: involvement of benzodiazepine systems.

Exposure to bedding taken from the soiled home cage of an isolated male resident elicited a significant increase in the nociceptive responses of male deer mice, Peromyscus maniculatus artemisiae, from mixed sex pairs. The analgesia induced by exposure to the male scent was insensitive to the opiate antagonist, naloxone, and was blocked by either pre- or post-olfactory exposure injections of the benzodiazepine antagonist, Ro 15-1788, or agonist, diazepam. This non-opioid analgesia was of brief duration (15-30 min) and rapid onset, being evident after 1 min of exposure to the olfactory cues. Bedding treated with the novel odor of peppermint also induced analgesia in the deer mice. This analgesia was opioid mediated, being blocked by naloxone and insensitive to the benzodiazepine manipulations. Exposure to either fresh bedding, or the soiled bedding of another mixed sex pair of deer mice, had no significant effect on nociception. These results indicate that exposure of male deer mice to the olfactory cues associated with a potentially threatening individual (dominant/aggressive isolated male) elicits an analgesic response that involves alterations in the activity of benzodiazepine systems.

Aggression↗
PubMed1990

The effects of intermittent dietary restriction on weight gain and body fat in white-footed mice, Peromyscus leucopus.

The effects of repeated food restriction-refeeding cycles were investigated in second generation captive Peromyscus leucopus. Mice were maintained on 50% of their individual predetermined ad lib diet for 5 days followed by 10 days of refeeding ad lib. Cycles were repeated 3 times. When compared with controls maintained ad lib for the same time period, no significant differences in final weight or fat content were observed. Restricted-refed mice were, however, observed to both lose and regain weight at increasing rates with each subsequent cycle.

Adipose Tissue↗
PubMed1995

Influence of photoperiod, green food, and water availability on reproduction in male California mice (Peromyscus californicus).

California mice (Peromyscus californicus) breed primarily during the winter rainy season and generally terminate breeding during the dry summer months. This pattern of reproduction could be regulated by day length, availability of green vegetation, or water availability. The effects of photoperiod and green vegetation on reproduction were examined in Experiment 1 by housing adult male P. californicus either in long (LD 14:10) or short (LD 8:16) photoperiods for 10 weeks with ad lib food and water availability. A subset of animals in each photoperiod treatment group also received supplements of fresh spinach thrice weekly. The effects of water availability were examined in Experiment 2 by housing adult males in long day length conditions for 10 weeks with ad lib or restricted (50% of ad lib) water availability. Neither photoperiod nor availability of green plant food significantly affected reproductive function in male California mice, although animals in long days with green food supplements displayed elevation of some reproductive organ masses. Short days did not suppress plasma LH or prolactin levels. Male P. californicus provide extensive care of the young during the short days of winter. The absence of photoperiod-induced changes in prolactin levels is consistent with the observation that elevated plasma prolactin titers are associated with male parental care in this species. In contrast, water restriction (simulated summer drought) reduced reproductive organ masses, as well as plasma levels of prolactin, and may act as an environmental cue to terminate breeding. Thus, water availability may regulate breeding in this species independently of photoperiod and food availability.

Animal Feed↗
PubMed1984

Maximum oxygen consumption during exercise and cold exposure in deer mice, Peromyscus maniculatus.

Convenient methods were developed for measuring maximum oxygen consumption (VO2 max) in untrained small mammals during treadmill exercise and cold exposure. Deer mice (Peromyscus maniculatus) were run once, for 6-min periods at velocities exceeding maximal aerobic running speed, while instantaneous oxygen consumption was measured. The VO2 max during cold exposure was determined using high wind speeds to increase heat loss rates. During running, the kinetics of gas exchange were rapid and similar to those observed in larger mammals. Half-times of the VO2 and VCO2 on-responses were about 20 sec. The VO2 also increased rapidly during suddenly imposed cold stress, reaching VO2 max within 1-1.5 min. Values of VO2 max obtained during exercise were similar to the VO2 max measured during cold exposure.

Animals↗
PubMed1984

Effect of naltrexone on food intake and hoarding in white-footed mice (Peromyscus).

Increases in food consumption and hoarding in mammals have been shown to be immediate and preparative adjustments to the energetic stresses of temperate winters. The sensitivity of these behaviors to the opiate antagonist naltrexone was tested in non-deprived white-footed mice (Peromyscus leucopus). Mice received naltrexone hydrochloride intraperitoneally (10 mg/kg in saline vehicle) once daily for four consecutive days subsequent to an equivalent period of injection with saline as control. Daily food intake was significantly (p less than 0.05) lower after naltrexone treatment. Hoarding, as assessed by logarithmic hoarding scores and the weight of cached food, was not affected by administration of this drug at this dosage. These results suggest that hoarding, a complex behavioral pattern that does not immediately affect internal energy stores, may not fall within the opiate regulatory scheme.

Animals↗
PubMed1986

Food hoarding and ingestion in the deer mouse, Peromyscus maniculatus: selective responses to mu and kappa opiate agonists.

The feeding behavior of the deer mouse, Peromyscus maniculatus, includes food hoarding as well as ingestion. Administration of the prototypical mu opiate agonist, morphine sulfate, 1-20 mg/kg, produced over three hours a significant dose-dependent stimulation of hoarding by free feeding deer mice. The specific kappa opiate agonist, U-50,488H, 0.10-10 mg/kg, markedly increased ingestion without having any augmentatory effects on hoarding. The mixed mu and kappa opiate agonist, ketocyclazocine hydrochloride, 1-10 mg/kg, as well as various combinations of morphine sulfate and U-50,488H, augmented both hoarding and ingestion. Food restriction for 24 hr caused a significant, naloxone (1.0 mg/kg) reversible, increase in food intake. Food deprivation also modified the hoarding and ingestion responses of the deer mice to the mu and kappa opiate agonists, reducing the relative amounts of food that were hoarded. These results indicate that mu and kappa opioid systems are differentially involved in the mediation of various aspects of feeding. This also suggests that environmental factors, such as food restriction, can modify the relative roles of mu and kappa opioid systems in the expression of feeding behavior.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1987

Sex and day-night differences in opiate-induced responses of insular wild deer mice, Peromyscus maniculatus triangularis.

We examined the effects of mu and kappa opiate agonists on the day- and night-time nociceptive, locomotory and ingestive behaviors of an island population of wild male and female deer mice, Peromyscus maniculatus triangularis. The prototypical mu opiate agonist, morphine, had significant analgesic and locomotory effects, which were blocked by naloxone, and the specific delta opiate antagonist, ICI 154,129, respectively. The specific kappa opiate agonist, U-50,488, had significant analgesic actions and inhibitory effects on locomotor activity, as well as stimulating feeding. Significant day-night variations occurred in the analgesic and activity responses, with the mu and kappa opiate agonists having significantly greater effects at night. There were also prominent sex differences in responses; male deer mice displaying significantly greater levels of mu and kappa opiate-induced analgesia and alterations in activity than female animals. These sex differences in opiate-induced effects were most pronounced at night, female deer mice displaying reduced day-night rhythms of responsiveness. These results demonstrate the existence of significant day-night rhythms and sex differences in the mu and kappa opiate behavioral responses of a wild population of rodents.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1989

Population differences in benzodiazepine sensitive male scent-induced analgesia in the deer mouse, Peromyscus maniculatus.

We compared opioid and nonopioid involvement in the mediation of scent-induced analgesia in two populations of deer mice, Peromyscus maniculatus; P. m. artemisiae from a mainland region and P. m. angustus from a small marine island. Exposure to bedding taken from the soiled home cage of an isolated (dominant aggressive) male resident elicited a significant increase in the nociceptive responses of male deer mice from mixed sex pairs, with the island population of mice displaying significantly greater analgesic responses than the mainland animals. In the mainland population of mice, the large amplitude analgesia induced by the scent of a conspecific was insensitive to the opiate antagonist, naloxone, but could be blocked by either the benzodiazepine antagonist, Ro 15-1788, or agonist, diazepam. Exposure to the scent of individuals from the island population elicited a lower amplitude analgesia that was sensitive to both the opiate and benzodiazepine manipulations. In the island population, both the lower amplitude analgesia induced by the scent of a conspecific and the higher amplitude analgesic elicited by the scent of a mainland animal was blocked by naloxone and only partially reduced by the benzodiazepine manipulations. Bedding treated with the peppermint also induced analgesia, with the island mice displaying a markedly greater analgesic response than the mainland animals. In both populations of deer mice the peppermint-induced analgesia was blocked by naloxone and insensitive to the benzodiazepine manipulations. These findings are considered in terms of their possible ecological significance and relations to the differences in agonistic and social behaviors between island and mainland populations of deer mice and other small rodents.

Analgesia↗
PubMed1985

Immunosuppression in experimental trypanosomiasis: effects of Trypanosoma equiperdum on the pathogenesis of influenza virus infection in deer mice (Peromyscus maniculatus).

The effects of Trypanosoma equiperdum infections on the immunological and pathological responses of deer mice (Peromyscus maniculatus) to influenza virus exposure were investigated. Mice carrying a 5 week trypanosome infection along with an age- and sex-matched trypanosome-free control group were simultaneously exposed to influenza Ao (WSN) virus. T. equiperdum infection significantly (P less than 0.01) converted a sub-lethal virus attack into a fatal pneumonic process in a small proportion of animals. In addition, the trypanosome caused a reduction (p less than 0.1) in virus replication on PID 1 and 2, accompanied later by a tendency towards virus persistence in the lungs of affected mice. This tendency was manifested by a log reduction in virus titres between PID 2 and 4 and PID 4 and 6 in the lungs of trypanosome-infected mice, compared to 2 log drops over the same periods in the lungs of control mice. T. equiperdum infection also significantly (p less than 0.001) depressed serum and pulmonary neutralizing antibody titres to influenza virus.

Animals↗
PubMed1984

Influence of feeding chlorocholine chloride and glyphosine on selected immune parameters in deer mice, Peromyscus maniculatus.

Exposure to the plant growth regulators, chlorocholine chloride (CCC) and glyphosine (GPS), resulted in significant immunomodulatory effects after feeding to deer mice (Peromyscus maniculatus) for 28 days. Cyclophosphamide (CP) and saline controls were included. Both CCC and GPS feeding levels were equivalent to 1, 10, 20, 40 and 80 mg/kg mouse/day. The parameters assessed were: spleen plaque forming cell (PFC) assays, hemolysin titers, white blood cell counts, bone marrow cellularity, hematocrits, plasma proteins, and spleen, liver, kidney, thymus and body weights. GPS significantly raised the ratio of liver/body wt, lymphocytes/g of spleen (at high doses only) and hemolysin titers (at low doses only). Lymphocyte viability was significantly reduced, while WBC counts and plasma protein levels were moderately lowered. CCC significantly reduced plasma proteins, PFCs/g of spleen, lymphocyte viability and hemolysin titers. It also affected thymus weights, WBC counts, lymphocytes/g of spleen and PFCs/10(6) lymphocytes. Most of the effects for both compounds followed a typical dose-response curve, but GPS gave a bimodal response in certain tests. The results demonstrate that CCC and GPS can act as immunomodulatory agents and show the feasibility of using deer mice for immunotoxicity studies of environmental contaminants and agricultural chemicals.

Animals↗
PubMed1984

Effects of ingestion of chlorocholine chloride and cyclophosphamide on Venezuelan equine encephalitis virus infections in deer mice (Peromyscus maniculatus).

We investigated the effects of chlorocholine chloride (CCC), a plant growth regulator, and cyclophosphamide (CP), a known immunosuppressant, on the ability of deer mice (Peromyscus maniculatus) to resist challenge with a sublethal dose of Venezuelan equine encephalitis virus ( VEEV ). The toxicants were continuously delivered in low doses in the feed; CP at 20 mg/kg body wt/day and CCC at 1, 10, 20 or 40 mg/kg body wt/day. Mice were inoculated with 3 X 10(4) plaque forming units (pfu) of VEEV after eating experimental feed for 23 days. Mice were bled daily for 7 days and at selected intervals from 8 to 63 days post inoculation (PI) for viremia and antibody titer determinations. CP treatment increased the duration of viremia and significantly (P less than or equal to 0.05) decreased mean viremia titers. Antibody titers were significantly (P less than or equal to 0.05) depressed in CP-treated mice compared to controls. CP treatment increased mortality. CCC had no effect on viremia duration or titer except when given in doses of 1 mg/kg body wt/day when it significantly (P less than or equal to 0.05) decreased mean viremia titers compared to controls. Early antibody responses were increased by CCC treatment except in the 10 mg/kg body wt/day treatment group in which titers were decreased. By 30 days PI antibody titers of CCC-treated mice were no different from controls.

Animals↗
PubMed1990

Effects of acute cold exposure at night on pineal N-acetyltransferase activity and melatonin content in white-footed mice, Peromyscus leucopus.

1. Pineal N-acetyltransferase (NAT) activity in long-day white-footed mice (Peromyscus leucopus) exposed to cold soon after onset of darkness was depressed relative to controls, whereas mice exposed to cold later at night had slightly elevated enzyme activity. 2. NAT activity in short-day mice exposed to cold soon after lights off did not differ from controls. Pineal melatonin in these mice, however, did not rise, as it did in controls. 3. These results suggest that acute cold exposure may modulate NAT activity, which is controlled primarily by the L:D cycle.

Acetyltransferases↗
PubMed1992

Correlations between serum corticosterone concentration and reproductive conditions in the white-footed mouse (Peromyscus leucopus noveboracensis).

1. Adrenal size and activity in reproductively inhibited young born into laboratory populations of the white-footed mouse were examined. Measurements were made of body weight, reproductive organ weight and adrenal weight. Serum corticosterone was measured by radioimmunoassay. 2. Data from reproductively inhibited animals were compared with corresponding values from reproductively capable animals of the same sex. The mean paired testis and seminal vesicle, or paired ovary and uterus, weights, were significantly reduced in reproductively inhibited animals of both sexes. The paired adrenal weights were not different in any comparison. 3. Reproductively inhibited males selected from laboratory populations had a mean corticosterone concentration that was significantly higher than the corresponding value for reproductively capable males. Females showed no significant difference in mean serum corticosterone concentrations. 4. The results are discussed in relation to earlier studies in two species of Peromyscus and the apparent paradox of elevated serum corticosterone in the absence of adrenal hypertrophy.

Adrenal Glands↗
PubMed1983

Comparative progesterone concentrations in two Peromyscus species.

1. Plasma progesterone concentrations were measured by radioimmunoassay in the oldfield mouse (Peromyscus polionotus) and the deermouse (P. maniculatus) at estrus and at 5-day intervals during pregnancy. 2. P. polionotus had significantly higher progesterone levels, both at estrus and during gestation. 3. The level was markedly less in female P. polionotus bearing interspecific (P. polionotus x P. maniculatus) hybrid conceptuses than in those with conspecific conceptuses. 4. It is postulated that the reduced progesterone level in females bearing hybrid fetuses may be responsible for reproductive failure which regularly occurs when this cross is attempted. 5. An endocrine difference of this magnitude could represent an incipient reproductive isolating mechanism.

Animals↗
PubMed1984

Kinetics of cytoplasmic aspartate aminotransferase from three genotypes of the deer mouse (Peromyscus maniculatus).

Three genotypic forms of the cytoplasmic enzyme, aspartate aminotransferase from the deer mouse (Peromyscus maniculatus) were each analyzed kinetically after partial purification. Kmapp and Vmax for aspartate decreased in value as temperature changed from 37.9 to 15 degrees C for all three forms. For the AA genotype, the binding enthalpies were highest at 37.9 degrees C and lowest at 25 degrees C, while for the A'A' form, they were lowest at 37.9 degrees and highest at 25 degrees C. Results for the heterozygote were generally intermediate reflecting the properties of both subunits. Inhibition by glyceraldehyde-3-phosphate was of a non-competitive type for all three genotypes.

Animals↗
PubMed2004

Sex differences in ultrasonic vocalizations and coordinated movement in the California mouse (Peromyscus californicus).

Geyer [Am. Zool. 21 (1981) 117] hypothesized that infant rodents increased the number of ultrasonic vocalizations when they moved in and out of the nest in order to elicit extended care from parents. We tested these hypotheses by recording ultrasonic vocalizations (USVs) and coordinated movements (locomotion and grooming) in California mouse and by recording USVs from pups before and after their parents retrieved them. In Experiment 1, USVs and coordinated movements were recorded from 2 to 30 days of age, in female and male Peromyscus californicus pups. USVs at 37, 42, 47, and 52kHz were digitized and recorded by computer and an event recorder program which was simultaneously used to record coordinated movement. Vocalizations persisted to 30 days of age. Vocalizations increased for both males and females after they spent more than 180s in coordinated movement and females vocalized more than males. Females also displayed more coordinated movement and earlier development of coordinated movement than males. There was no effect of litter size on USVs. In Experiment 2, the number of USVs emitted by pups and the latency of dams and sires to contact their pups and retrieve them was measured. There was no significant correlation between the number of USVs emitted by pups and the latency for a parent to contact or retrieve a pup. Results from Experiment 1 provided some support for Geyer's (1981) hypothesis and results from Experiment 2 did not support the hypothesis that the main function of USVs in California mouse pups was to elicit parental care.

Acoustic Stimulation↗
PubMed2005

Identification of a monoclonal antibody from Peromyscus maniculatus (deer mouse) cytomegalovirus (PCMV) which binds to a protein with homology to the human CMV matrix protein HCMV pp71.

In this study we identified and characterized a monoclonal antibody against the matrix protein of a cytomegalovirus isolated from the common deer mouse (Peromyscus maniculatus) (PCMV). The monoclonal antibody was isolated using previously described technology which could be applied to the production of monoclonal antibodies against zoonotic disease. The antibody was found to react with a protein homologous to the human cytomegalovirus (HCMV) matrix protein (pp71), the product of the UL82 open reading frame (ORF). mAbs were generated from heterologous fusion of spleen cells from PCMV-positive mice and Balb/C P3X63-Ag8.653 myeloma cells. Using this approach, four monoclonal antibodies: B8C4, C12E8, G6A2 and P4E5 were generated. Antibody G6A2 reacted strongly with PCMV-infected cells as well as purified virions on ELISA and immunofluorescence. Western blot analysis, using sucrose gradient-purified virions, demonstrated that this mAb reacted specifically to a single protein with an apparent molecular weight of 71 kDa. The protein band was excised from the gel, purified and subjected to trypsin digestion followed by mass spectrometry. The protein sequences obtained were found to have identity to HCMV UL82 gene product. Sequence analysis indicated that it is the putative HCMV pp71 protein homolog of PCMV. G6A2 mAb did not cross-react with either human or murine recombinant pp71 proteins expressed in mammalian cells.

Amino Acid Sequence↗