1998 Fiscal Year Final Research Report Summary
The experimental study of the photoiperiodic enviroment with controls testes and body weight in the animals.
| Project/Area Number |
08610081
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
実験系心理学
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| Research Institution | Shiga Univ. |
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Principal Investigator |
IBUKA Nobuo Shiga Univ., Facutly of Education, Prof., 教育学部, 教授 (70110757)
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| Project Period (FY) |
1996 – 1998
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| Keywords | photoperiodism / testis / body weight / development / Syrian hamster / stres |
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| Research Abstract |
Laboratory rats, mouse and guinea pigs do not regress their testes under long-term exposure to a short photoperiod (SP), On the other hand the testes of hamsters regress under SF exposure. This characteristics of the animal is called photoperiodism. A series of experiments investigated the interactive effects of photoperiodic environment with chousing. diet. and the Partner's sex on the growth or testes. and body weight in the Syrian hamsters.
First. photoperiodic response to SP was examined in Mongolian gerbils. The change of testicular and epididymal weight as well as body weight was measured as a function of SP exposure of LD 8 : 16. It was round that Mongolian gerbils could discriminate between a long photoperiod (LP.LD16 : 8) and SF.Their testes as well as epididymides regressed and spontaneously redeveloped under SP.Mongolian gerbils were determined to be classified as a photoperiodic species.
A series of experiments clarified that the growth of testes was suppressed when the animals were exposed to SP and" were given vegetable chow (ZF). Chousing with a peer prevented the atrophy of testes while it facilitated body growth. The growth of testes was most suppressed when the animals were given ZF chow and lived singly under. SP.It was also found that chousing with a peer had facilitative effect on testes growth, but the effect of sex or a peer on testes growth could not be found. Finally the stressful effect caused by unpredictable deprivation of water was alleviated by cohousing with a peer.
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