1994 Fiscal Year Final Research Report Summary
The relationship between stress and unpredictable deprivation
| Project/Area Number |
05610063
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
実験系心理学
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| Research Institution | SHIGA UNIVERSITY |
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Principal Investigator |
IBUKA Nobuo Shiga University, Faculty of Education.Professor, 教育学部, 教授 (70110757)
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| Project Period (FY) |
1993 – 1994
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| Keywords | stress / gonads / body weight / hibernation / photoperiod / syrian hamster |
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| Research Abstract |
The experiments were performed to investigate the effect of stress on testicular weight and body mass in young adult Syrian hamsters under long or short photoperiods. We hypothesized that water or food deprivation causes stress and that the amount o stress depends on unpredictable timing of deprivation. More specifically, water or food deprivation on unpredictable days was considered more stressful for animals than regular deprivation on fixed days even if the total lengths of deprivation were the same for the two treatments.
Exp.1 showed that water deprivation on unpredictable days caused more suppressive effects on testicular weight and body mass than that on fixed days. Exp.2 indicated that unpredictable food deprivation on a quarter or half of the days throughout the 12-week test period under short photoperiod also induced more detrimental effects on testes and body growth than predictable deprivation on every 4 days or every other day. These findings clearly suggested that the stress associated with water or food caused more suppressive effects on testicular and body mass than the shortage of water or food per se.
The stress on hibernation was also investigated in the Syrian hamster. It was hypothesized from our previous findings that unpredictable deprivation of water caused more stress for animals than regular deprivation. The results showed that the animals of the random and unpredictable deprivation entered hibernation more readily, and for longer period than those of regular deprivation, or the control animals with no deprivation.
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