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Two strains of roof rats as effective models for assessing new-object reaction.

ABSTRACT: Wild animals generally avoid even small and harmless novel objects and/or familiar objects moved to a novel position, which is termed "new-object reaction". Although new-object reaction appears to be a biologically important characteristic for animals, little progress has been made in understanding the neural mechanisms underlying new-object reaction. One reason might be the lack of effective experimental animals. Two strains of roof rats (Sj and Og strains) were established from wild roof rats caught in Shinjuku, Tokyo and one of the Ogasawara Islands, respectively, by a Japanese pest control company. Based on the rat caregivers' informal observations, we conducted behavioral and anatomical tests to assess the validity of Sj and Og strains for the analyses of new-object reaction. In Experiment 1, the Sj strain showed reduced food consumption compared with the Og strain when food was provided in a novel way, suggesting that the Sj strain had a stronger avoidance of novel objects compared with the Og strain. Experiment 2 demonstrated that the basolateral complex of the amygdala and bed nucleus of the stria terminalis in experimental Sj rats had a larger percentage area compared with that of experimental Og rats, indicating these nuclei might be involved in the difference observed in avoidance of novel objects between the strains. Taken together, the present study suggests that Sj and Og strains are effective experimental animals for assessing new-object reaction.

SUBMITTER: Kiyokawa Y

PROVIDER: S-EPMC5402190 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

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Two strains of roof rats as effective models for assessing new-object reaction.

Kiyokawa Yasushi Y Tanaka Kazuyuki D KD Ishii Akiko A Mikami Kaori K Katayama Masatoshi M Koizumi Ryoko R Minami Syota S Tanikawa Tsutomu T Takeuchi Yukari Y

The Journal of veterinary medical science 20170216 4

Wild animals generally avoid even small and harmless novel objects and/or familiar objects moved to a novel position, which is termed "new-object reaction". Although new-object reaction appears to be a biologically important characteristic for animals, little progress has been made in understanding the neural mechanisms underlying new-object reaction. One reason might be the lack of effective experimental animals. Two strains of roof rats (Sj and Og strains) were established from wild roof rats ...[more]

PMID: 28202879

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Project description:ObjectivesDuring the COVID-19 pandemic wearing a mask in public has been recommended in some settings and mandated in others. How often this advice is followed, how well, and whether it inadvertently leads to more disease transmission opportunities due to a combination of improper use and physical distancing lapses is unknown.DesignCross-sectional observational study performed in June-August 2020.SettingEleven outdoor and indoor public settings (some with mandated mask use, some without) each in Toronto, Ontario, and in Portland, Oregon.ParticipantsAll passers-by in the study settings.Outcome measuresMask use, incorrect mask use, and number of breaches (ie, coming within 2 m of someone else where both parties were not properly masked).ResultsWe observed 36 808 persons, the majority of whom were estimated to be aged 31-65 years (49%). Two-thirds (66.7%) were wearing a mask and 13.6% of mask-wearers wore them incorrectly. Mandatory mask-use settings were overwhelmingly associated with mask use (adjusted OR 79.2; 95% CI 47.4 to 135.1). Younger age, male sex, Torontonians, and public transit or airport settings (vs in a store) were associated with lower adjusted odds of wearing a mask. Mandatory mask-use settings were associated with lower adjusted odds of mask error (OR 0.30; 95% CI 0.14 to 0.73), along with female sex and Portland subjects. Subjects aged 81+ years (vs 31-65 years) and those on public transit and at the airport (vs stores) had higher odds of mask errors. Mask-wearers had a large reduction in adjusted mean number of breaches (rate ratio (RR) 0.19; 95% CI 0.17 to 0.20). The 81+ age group had the largest association with breaches (RR 7.77; 95% CI 5.32 to 11.34).ConclusionsMandatory mask use was associated with a large increase in mask-wearing. Despite 14% of them wearing their masks incorrectly, mask users had a large reduction in the mean number of breaches (disease transmission opportunities). The elderly and transit users may warrant public health interventions aimed at improving mask use.

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Two strains of roof rats as effective models for assessing new-object reaction.

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Two strains of roof rats as effective models for assessing new-object reaction.

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