2007 Fiscal Year Final Research Report Summary
RNAi-induced change in the expression of estrogen receptor α in the median preoptic nuclei of mother rats and its effects on the behavior of their offsprings.
| Project/Area Number |
17390555
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Orthodontic/Pediatric dentistry
|
|---|
| Research Institution | The Nippon Dental University |
|---|
Principal Investigator |
OGUCHI Haruhisa The Nippon Dental University, School of Life Dent., Guest Prof (30124689)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
SHIRAKAWA Tetsuo Nihon Univ., School of Dent., Prof (00187527)
MITOME Masato Tokushima Univ., Grad. School of Health Biosci., Prof (50261318)
HASEGAWA Tomokazu Kyushu Univ., Hospital, Assist Prof (50274668)
KIKUIRI Takashi Hokkaido Univ., Grad. School of Dent. Sci., Assist Prof (10322819)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Keywords | gene / neuroscience / brain and nerve / maternal behavior / median preoptic nucleus / estrogen / receptor / in vivo micro-CT |
|---|
| Research Abstract |
Targeted ectopic silencing of genes is an invaluable approach for studying the role of hormones/neurotransmitters and their receptor functions in the brain. We devised a strategy that allows localized in vivo transfer of siRNA or transfection of plasmid DNA encoding shRNA by electroporation within the median preoptic nuclei (POA) of rats.
Injection of plasmid DNA into the hypothalamic areas including the POA of adult female rats, followed by application of electrical current via bipolar electrodes, resulted in intracellular delivery of DNA. We used a cocktail of plasmid DNA encoding EGFP and three siRNAs against estrogen receptor α (ERα), and found that EGFP was expressed widely at around the injection sites. With an examination of the brain sections obtained from the electroporated animals, we found that the number of ERα-positive neurons decreased at 4th day after the electroporation.
Electroporation of plasmid DNA encoding shRNA against ERα caused suppression of the ERα expression for longer period (about 2 weeks) at around the injection sites. It was shown that this strategy could be used for gain-or loss-of-function experiments. Using this approach, we identified an essential role for ERα in maintaining the maternal behaviors. Thus, we recognized that in vivo electroporation provides a new approach to study the brain functions implicated in mother-pups interactions.
Craniofacial bony sizes and occlusion during the developmental stage were examined in male SD rats by in vivo micro-CT. Most of the rats aged 3-13 weeks showed posterior cross bite, which was the first report of occlusion in rats in vivo. Complete Freund's adjuvant (CFA) was injected into the temporomandibular joint (TMJ) cavity of rats and osseous abnormalities in the condyle were observed after CFA injection. We conclude that in vivo micro-CT is suitable for detecting changes in the bone architecture of small animals.
|
