新的研究表明REM是关于眼睛不是梦想

纽约，纽约，1998年2月11日——哥伦比亚大学的一名研究人员“颠覆了”快速眼动睡眠(REM)功能的传统观点。据哥伦比亚长老会医学中心眼科学系的眼生理学教授大卫·莫里斯博士说，快速眼动睡眠与视力的关系可能比与梦境的关系更大。这项发表在2月13日《实验性眼睛研究》(Experimental Eye research)杂志上的研究表明，眼角膜后方前房的透明水状液体房水需要循环，将氧气从虹膜血管输送到眼角膜。当眼睑在睡眠中闭上时，血液循环大大减慢，快速的眼球运动只是为了“搅动”前房，防止角膜窒息。在20世纪50年代，研究发现，当睡眠者的眼睛在眼皮下快速转动时，如果他们被唤醒，他们经常能回忆起自己做的梦。从这些发现中演化出一个流行的理论，即在REM睡眠期间，大脑在清醒时处理收集到的信息，“就像商店在清点存货时关门营业，”莫里斯博士说。“由于其对中枢神经系统功能的影响，REM被认为是从心理学到神经药理学的学科领域，但它还没有受到眼生理学家的关注。”莫里斯博士为快速眼动睡眠提出了一个完全不同的目的。当他得知一个年轻人的眼睛在一次事故中被固定住，他的角膜被血管缠结，可能是为了给角膜提供氧气时，他发展了自己的理论。莫里斯医生知道，当眼睛闭上时，氧气只能通过前房停滞的水的扩散，从虹膜进入角膜。 Using mathematical calculations, he established that under these circumstances, the oxygen supplied will be insufficient and corneal suffocation possibly leading to cell death will result. To demonstrate that aqueous circulation virtually stops when the eyelids are closed, Maurice stained the aqueous with a fluorescent dye and charted its currents. In a closed eye, freshly secreted unstained aqueous from behind the iris accumulated in front of the pupil as a dark pool. But when the eye opened, the pool quickly rose within the anterior chamber and began to circulate. It has long been established that in an eye opened to cooler room air, convection currents based on heat differentials cause the aqueous to circulate. In other experiments, moving the eyes voluntarily immediately stirred up the fluorescence in the chamber so that it became uniform. Dr. Maurice's "stagnant aqueous humor hypothesis" could explain why periods of REM sleep initially last about 20 minutes but become progressively longer as the night wears on. And the fact that the womb is at uniform temperature could explain why REM is so active in the fetus. If taking sensory inventory is the purpose of REM sleep, why does an unborn child spend many hours a day in REM? he asks. Likewise, why do animals born with sealed eyelids need REM? "It is quite possible," states Dr. Maurice, "that REM sleep evolved with the primary purpose of protecting the cornea." And what of our dreams? Dr. Maurice does not deny that REM sleep is associated with such phenomena as dreaming, a rise in brain temperature, penile erections, and EEG changes. But he cannot see any physiological significance in these phenomena and suggests that they may result from the partial arousal necessary for REM to occur. "In any case," he writes, "my interests are in the plumbing, and I am happy to leave dreams to others."