Mallick B N, Gulyani S
School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
Neuroscience. 1996 Dec;75(3):729-36. doi: 10.1016/0306-4522(96)00177-7.
Rapid eye movement sleep deprivation alters behavioral and physiological, as well as cellular functioning and responsiveness. Since intracellular calcium concentration plays an important role in regulating cellular functions, it was hypothesized that such deprivation might induce changes in intracellular calcium concentration. Therefore, in this study, rats were deprived of rapid eye movement sleep by the flower-pot technique, and total, bound and free calcium concentrations were estimated in synaptosomal preparations from the cerebrum, cerebellum, brainstem, midbrain, pons and medulla. Rapid eye movement sleep deprivation was continued for two or four days and suitable control experiments were conducted to rule out the effects of non-specific factors. Total calcium concentration increased in the brainstem but showed a decrease in the cerebellum and cerebrum. After four days deprivation, the free calcium concentration always decreased; however, the bound calcium concentration decreased in the cerebrum and cerebellum but increased in the brainstem. After two days' deprivation, the medulla was the only region where the bound calcium increased while the free form decreased; only the free form decreased in the pons, while the midbrain was never affected. The results suggest that there was a net efflux of calcium in the cerebellum and cerebrum, but a net influx in the brainstem. The findings support our hypothesis and help to explain earlier observations. Since it is known that calcium plays an important role in cellular functioning, these changes in calcium concentration may be the underlying mechanism for rapid eye movement sleep deprivation-induced cellular expressions and behavior of neurons.
快速眼动睡眠剥夺会改变行为和生理机能，以及细胞功能和反应性。由于细胞内钙浓度在调节细胞功能中起重要作用，因此推测这种剥夺可能会导致细胞内钙浓度发生变化。所以，在本研究中，采用花盆技术剥夺大鼠的快速眼动睡眠，并测定大脑、小脑、脑干、中脑、脑桥和延髓突触体标本中的总钙、结合钙和游离钙浓度。快速眼动睡眠剥夺持续两天或四天，并进行了适当的对照实验以排除非特异性因素的影响。脑干中的总钙浓度升高，但小脑和大脑中的总钙浓度降低。剥夺四天后，游离钙浓度总是降低；然而，结合钙浓度在大脑和小脑中降低，但在脑干中升高。剥夺两天后，延髓是唯一结合钙增加而游离钙减少的区域；脑桥中只有游离钙减少，而中脑从未受到影响。结果表明，小脑和大脑中有钙的净流出，但脑干中有钙的净流入。这些发现支持了我们的假设，并有助于解释早期的观察结果。由于已知钙在细胞功能中起重要作用，这些钙浓度的变化可能是快速眼动睡眠剥夺诱导的细胞表达和神经元行为的潜在机制。
