神經膠質細胞起著保護以及承托腦部神經元的作用，正如其希臘語中的意思「膠水」一樣。但最近科學家發現，神經膠質是腦可塑性的中心，在學習及記憶上扮演著重要的角色。
In its Greek meaning for
“glue”, Glia cells support and link neurons together. Scientists have recently
discovered the importance of glia in learning and memory, as the centre of
brain’s plasticity.
腦主要由兩種細胞組成，分別是神經元及神經膠質。神經元傳遞神經脈衝控制著我們的思想行為，並且在神經元末端的突觸，透過神經遞質將訊息傳遞到另一神經元。科學家認為記憶及學習受到突觸的活性支配，因為突觸活性是可塑的，能夠影響適應不同刺激的能力。腦部訊息發源自神經元，經突觸傳遞，而神經膠質則協調了整個網絡。它可以促進及抑制訊息傳遞，使腦部在學習及記憶功能達至最佳狀態。神經膠質就像管理員一樣，能夠控制神經遞質在神經元間突觸中的傳遞，藉此影響腦部處理資訊及學習的過程。
The main components of
brain are neuron cells and glia cells. Neurons administer thinking and behaviour
through nerve impulses, transmitted to another neuron by synapse through
neurotransmitters. The plasticity of synaptic activity influences our ability
to adapt to different stimuli, which handles memory and learning. Neurons are
the source of messages, transferred between synapses, while glia cells regulate the whole network. The facilitation or suppression
of message transfer optimises the brain function with respect to learning and
memory. Orchestrating the transfer of neurotransmitter in synapse between
neurons, glia seems like a conductor to direct the information process and
learning.
 |
| 紅色的是神經元網絡，綠色的是神經膠質細胞，而藍點是神經元的細胞核。 A network of neurons is shown in red, glia cells are shown in green and blue dots are the nuclei. Photo: Pablo Blinder. |
Hippocampus and cortex
control the information process, learning and memory in brain, which was found
glia cells in abundance. The proportion of neuron to glia is 1:2-5.
幾乎所有腦神經退化性的疾病都是神經膠質的病變。例如當腦癇症發作時，由於神經膠質不能協調突觸傳輸，個別神經元的過度活性會不由自主地擴張到其它神經元，最終會不受控制。
Glia pathologies were found
in almost all neurodegenerative diseases. When epileptic seizures occur, the
overactive neurons at one area uncontrollably spread out other areas because of
the failure of glia in regulating synaptic transmission.
以色列特拉維夫大學的研究員研發了首套電腦模擬程式，用以展示神經膠質對突觸資料傳遞的影響，這套程式能夠協助研究一些腦部疾病，例如腦退化症以及腦癇症。這些新發現亦改寫了神經科學對這膠水的看法，令我們更了解腦部如何協調訊息的傳遞。
To demonstrate the effect
of glia on synaptic transmission, Tel Aviv University researchers have built
the first computer model which boosts the research on brain disorders such as
Alzheimer’s disease and epilepsy. The new discovery helps us understand deeply
about the regulation of neurotransmission in brain and revises the formulation
of glue in neuroscience.
Sora Siu
Reference:
Brain's Connective Cells Are Much More Than Glue. (2011, Dec 29). Retrieved Dec 30, 2011, from American
Friends of Tel Aviv University:
http://www.aftau.org/site/News2?page=NewsArticle&id=15751
No comments:
Post a Comment