1 |
親子分離對新生老鼠之腎上腺發育的影響 / The effects of maternal separation on the development of adrenal glands周斈澧 Unknown Date (has links)
腎上腺素為哺乳類為了因應各種不同的壓力所釋放出的物質,影響生物體日常的生理功能且對生物體的存活有著莫大的貢獻,在成體中的調節已經在很多文獻中被探討,但對於處在發育階段的新生兒其腎上腺的發育與早期壓力對此系統的影響仍不盡清楚。為探討壓力與腎上腺發育及壓力調控之間的關係,本論文將觀察之重點放在腎上腺髓質中能夠製造腎上腺素的嗜鉻細胞(chromaffin cells)上。要了解新生兒腎上腺發育與壓力之間的關係,主要是利用親子分離的實驗,對新生老鼠造成壓力,實驗將新生老鼠分成三組,分別為控制組(control)、隔離組(isolate;P2~P14一小時/天)與撫摸組(handle;P2~P14 十分鐘/天),試驗完畢後分別在老鼠出生後十四天(P14)與出生後二十一天(P21)進行腎上腺切片,利用腎上腺素合成酵素(PNMT ,phenylethanolamine-N-methyl transferase)及腎上腺素與正腎上腺素共同合成酵素(TH,tyrosine hydroxylase)之螢光免疫染色,來區分可製造腎上腺素的chromaffin cells,發現不管在P14或是P21,三組之間的腎上腺髓質結構並無太大差異。結果顯示,經過親子分離實驗的操弄,發現在撫摸組chromaffin cells中其PNMT的含量相對於TH的比例含量高於控制組與隔離組,顯示在撫摸組中每一chromaffin cell含有較多的PNMT,可能可以製造較多的腎上腺素。最後,為探討親子分離實驗對新生老鼠之腎上腺素與正腎上腺素含量的影響,以HPLC檢測經過親子分離實驗的新生老鼠之腎上腺,發現在P14時撫摸組與隔離組之腎上腺素含量比控制組高(p<0.05),而正腎上腺素的含量則沒有差異;在P21時三組間的腎上腺素與正腎上腺素含量則沒有差異。而同樣的親子分離實驗在一胎一組新生老鼠的腎上腺發育上未看到任何顯著影響。
|
2 |
電刺激大鼠側韁核對區辨性低頻操作式制約行為的影響 / The effects of electrical stimulation in the lateral habenula on operant behavior maintained by the differential reinforcement of low-rate (DRL) schedule of reinforcement in the rat林禧岳 Unknown Date (has links)
透過神經科學的研究,對於大腦的行為功能已有一定的認識,不同於以往的認識,目前認為神經行為機制不只由單一腦區或單一神經化學系統所調控。深部大腦電刺激經常被用來研究特定腦區的行為功能。但是,深部大腦電刺激的作用機制仍然不清楚。最近幾年臨床研究發現,利用電刺激在側韁核成功的治療憂鬱症患者。然而,目前認為側韁核與多巴胺系統互為負回饋作用,共同參與在動機行為的酬賞反應中。本實驗室先前的研究顯示,破壞韁核造成區辨性低頻操作式制約行為 (簡稱DRL行為)學習的障礙,然而,電刺激在側韁核造成DRL行為表現的結果還是未知的。所以,本實驗主要以電刺激在側韁核觀察大鼠行為上的改變,探討側韁核在行為上參與的功能。實驗一的結果顯示電刺激在側韁核並不影響自發性運動能力,在不同電流強度的刺激下也不會影響。實驗二的結果顯示電刺激在側韁核造成DRL 15秒的行為有類安非他命效果之行為表現,在高頻率電刺激有較顯著類安非他命的效果。實驗三的結果顯示電刺激在側韁核造成DRL 15秒的行為之影響,會被多巴胺受體抑制劑所抵消,而單獨注射巴胺受體抑制劑並不影響DRL 15秒的行為。實驗四的結果顯示電刺激在側韁核造成DRL 15秒的行為之影響,不會被正腎上腺素受體抑制劑所抵消。實驗五的結果顯示電刺激在側韁核造成DRL 72秒的行為之影響並不如DRL 15秒的行為顯著。實驗六的結果顯示電刺激在側韁核並不會造成大鼠無法區辨酬賞的量。綜合而言,側韁核在動機行為的角色,是透過影響多巴胺系統造成行為的改變。 / Behavioral function of the brain has been studied in neuroscience and progressively accumulated informative data to reveal the neurobehavioral mechanisms. It is now realized that those underlying mechanisms of behaviors is not as such simple as previous thought of limiting only in one locus of the brain or solely by one neurochemical system. The deep brain stimulation is usually used to study the behavioral function of specific brain regions. However, the mechanism of the deep brain stimulation is still unclear. The previous study has shown that electrical stimulation of the lateral habenula (LHb) successfully treated depression symptoms in the patients. It is proposed that an inhibitory role of LHb on the mibrain dopamine (DA) system which mediates the reward-related behavior. A previous study of this lab showed that lesion of habenula impaired the acquisition of differential reinforcement of low-rate responding (DRL) behavior. But, the effect of LHb stimulation on the DRL behavior is still unclear. To determine the functions of LHb involving in the behavior, the electrical stimulation was applied in LHb to observe the behavioral change of rats. The results of Experiment 1 showed that the LHb stimulation had no effect on locomotor activity. In Experiment 2, the LHb stimulation was shown to affect DRL 15-s behavior, which effects were similar to those affected by amphetamine. Experiment 3 showed that the DA receptor antagonists reversed the effects of LHb stimulation, while experiment 4 showed that norepinephrine (NE) receptor antagonists had no reversal effect on DRL 15-s behavior. In Experiment 5, the amphetamine-like behavior induced by LHb stimulation had subtle effects on DRL 72-s behavior. Experiment 6 showed that the LHb stimulation had no effect on a discrimination task. These data suggest that the LHb modulating DRL behavior is DA-dependent.
|
Page generated in 0.0154 seconds