1. RETICULAR FORMATION AND AROUSAL/SLEEP
這種起初認為混亂，鬆散，的地區現在是許多研究人員努力發展，找尋人類行為的指標，它不僅僅在研究中重要，更是人體不可或缺的。
Reticular formation是大腦的一部份，它是由超過100種的網狀神經結構所組成，類似一種過濾網(如圖中所示)，
它處於一個訊息傳入通道的中間，能夠過濾所傳進大腦的刺激，以達到分辨刺激的來源，這種結構對於高等生物行
使基本的行為能力有非常大的幫助，對於調節意識和警醒是非常重要的 !
history
71 湯燕傑
79 廖于樟

2. Structure of RF reticular formation在延髓，橋腦，中腦組合成了一個系統，向下到脊髓向上到丘腦及深度丘腦。
在橋腦中由中、小型三角形和梭形細胞所組成，橋腦神經連接了延隨與中腦，在中腦中則由中、小型三角形、棱形或橢圓形细胞组成；
在1957年Brodal指出Reticular formation具有明確的細胞構造，能夠連繫內與外的區域，
如此構造不僅僅控制高等脊椎動物的清醒與睡眠，亦參與血壓，呼吸等調節作用。

3. RETICULAR FORMATION –AFFERENT & EFFERENT CONNECTIONS OF RETICULAR FORMATION
Optic, auditory olfactory and taste pathways
Sensory Pathways
Cerebellum
Substancia Nigra
Thalamus
Cortex
Reticular Formation
Red Nucleus
Reticular Formation
Cerebellum
Cortex SC SC
Tectum
reticular formation是一個訊息傳入和傳出的中站，是複雜神經徑路，控制自主功能，痛覺，眼球，和心跳的路徑，
他們本身的樹突，軸突與來自不同細胞的軸突混在一起，經過複雜的迴路聯絡大腦皮層，達到連結控制的功能。
如上圖所示，訊息從各種不同的地方傳入，在傳出到各個相對應的行為上。
(Touch, pain, temperature, kinesthestic sensation)
Thalamus, Hypothalamus
Corpus Striatum
EFFERENT CONNECTION TO THE RETICULAR FORMATION
AFFERENT CONNECTION TO THE RETICULAR FORMATION

4. Sleep Centres actually generate sleep
hypothalamus (ant: awakening, post:sleep)
reticular formation
area below midpons
(cholinergic, serotoninergic ->sleep
adrenergic -> wakefulness)
sleep generating substances in CSF after long sleep deprivation
睡覺會使人體產生許多不同物質進入腦脊髓液，控制警醒和睡眠，例如:
reticular formation在無光源之下，產生膽鹼，血清素則為睡著，
產生腎上腺素則為清醒。

5. Reticular activating system
The reticular activating system (RAS) is an area of the brain responsible for regulating arousal and sleep-wake transitions.
Regulating Sleep-Wake Transitions – electrical activity
The relationship between RAS and sleep-wake
Attention
reticular formation 對警醒，睡眠，的調節是不可或缺，重要的。
網狀活動系統(RAS)是腦幹及視丘內的複雜神經徑路，可接收脊髓及其他部分的神經訊息,經過複雜的迴路聯絡大腦皮層，
且RAS活動活躍起來時會感到醒覺，並維持清醒，相對的當RAS活動慢下來時，就會引起睡眠，
並且RAS可以調節人從睡眠到清醒的的那段時間，生理的反應。
RAS是利用丘腦與大腦皮質的功能，產生不同電波，其不同頻率有著不同的睡眠關係

6. BRAIN WAVES AND AROUSAL/SLEEP
Awake
Slow-wave sleep
REM
Deep sleep
1.清醒的意識，高亢興奮，腦波頻率約30Hz~40Hz以上。
2.清醒的意識，日常生活，腦波頻率約12Hz~30Hz以上。
3.半意識(做夢期)，Alpha，舒緩狀態(打盹)，腦波頻率約12Hz~8Hz(劣質睡眠品質)。
4.無意識狀態(深睡)，眼球快速轉動，腦波頻率約8Hz~4Hz(優質睡眠品質)。
5.無意識狀態(內分泌期)腦波頻率約0.1Hz~4Hz(最優質睡眠品質)

7. REGULATION OF SLEEP
Stimulation of certain specific areas of the brain can produce sleep with characteristics near those of natural sleep, such as:
The raphe nuclei in the lower half of the pons & in the medulla;
The nucleus of the tractus solitarius;
Several regions of the diencephalon, such as rostral portion of the hypothalamus ( mainly in the suprachiasmal area) & an occasial area in the diffuse nuclei of the thalamus.
Which send fibers to the brain stem reticular formation & also to the hypothalamus, thalamus, most of the areas of the limbic system, to the neocortex & also to the SC;
在腦中特定區域的刺激，及產生的激素(血清素)會造成人，高等脊髓動物的清醒及睡眠。
腦中神經纖維的末梢產生血清素，幫助睡眠品質提升，但如果被阻斷，將會好多天睡不著。
結論許多區域都能影響清醒及睡眠的工作。
Many nerve endings from these fibers produce SEROTONIN, that if blocked doesn’t allow the production of sleep for several days.

8. Lesions in the raphe nuclei lead to high state of wakefulness;
REGULATION OF SLEEP
Lesions in the raphe nuclei lead to high state of wakefulness;
Bilateral lesions in the medial rostral suprachiasmal area in the anterior hypothalamus also cause wakefulness;
In both cases, the excitatory reticular nuclei of the mesencephalon and upper pons become released from inhibition, thus causing INTENSE WAKEFULNESS
如果reticular formation產生病變，在神經會不受控制加強清醒的感覺，
造成持續的維持清醒無法睡眠，或是昏迷，嚴重甚至造成死亡。
These type of lesions can lead to death of the animal due to exhaustion.

9. There are also other possible transmitter substances related to sleep
REGULATION OF SLEEP
There are also other possible transmitter substances related to sleep
in the CSF, in blood or urine of animals kept awake over a long period,there are substances that cause sleep when injected into the brain ventricular system of another animal.
還是有許多物質可進入腦中引響睡眠，例如:
MURAMYL PEPTIDE
此種物質在腦中產生時會讓人感覺到睡意，想睡覺。
MURAMYL PEPTIDE in CSF;
Another nonpeptide isolated from blood of sleeping animals;
Another unidentified substance found in the neuronal brain stem of animals, causes the accumulation of sleep factors ( in CSF or in the brain stem) leading to sleep.

10. CYCLE BETWEEN SLEEP & WAKEFULNESS
There’s yet no explanation for the reciprocal operation of the sleep-wakefulness cycle;
But some suggest that when the sleep centers are NOT activated, the mesencephalic & upper pontile RAS are released from inhibition, which allows the RAS to become spontaneously active;
This will excite PNS & Cerebral Cortex, both of which send POSITIVE FEEDBACK to the same reticular activating nuclei to activate them still further;
So, once wakefulness starts it has a natural tendency to sustain itself;
After a few hours, the brain & even neurons themselves become fatigued & the positive feedback fades & sleep- promoting centers take over.
現在Reticular formation控制警醒和睡眠的機事尚未明瞭，大概猜想為睡眠中心尚未啟動時，
RAS會自然激發產生活動，激活之後會正回饋reticular activating nuclei持續維持清醒，
等到數小時過去，等神經細胞感到疲累，正回饋消失，漸漸感到疲累。

11. Other Function Somatic motor control Cardiovascular control
Pain modulation - The reticular formation is one means by which pain signals from the lower body reach the cerebral cortex.
Sleep and consciousness
Habituation
Dream
reticular formation還包含相當多的功能，大致上可分為以下幾類，
第一、許多運動神經傳送訊息進入reticular formation，然後reticular formation再依靠從眼睛和耳所傳來之訊息(刺激)，經過綜合後調節運動。
第二、reticular formation包含血管舒縮的中心—延髓，控制一部分的血管舒縮。
第三、reticular formation是下行身體痛覺傳入的必經路徑，所以是下行鎮痛的重要因素，可阻擋一些痛覺訊息傳入大腦皮質。
第四、1reticular formation可以投影在丘腦和脊髓，幫助發揮控制能力，幫助維持清醒狀態，引起覺醒警戒和注意辦眼中心，是重要的角色。
第五、reticular formation與平常的習慣有相當大的關聯，例如 : 長期處在吵雜中，依然能夠睡著。
第六、腦幹經由 reticular formation發射至大腦皮質的電位訊號符合某一種頻率範圍時，大腦皮質的活動狀態，稱為夢。
種種的功能對於人行使能力都是不可或缺的，假如缺失，都是極大的傷害，損失。

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