- white matter
Brain tissue is divided into two types: gray matter and white matter. White matter is made up of the axons of neurons -- the long filaments that extend from the cell bodies and carry the electrical signals that carry the messages between neurons. It's the myelin sheathing that makes it look white. There are three major white matter systems, which all connect to form one continuous system: cortical white matter; the corpus callosum; the internal capsule.
White matter tracts are classified according to their pathways:
• projection tracts encompass those that project from the cortex to non-cortical areas, such as the senses and the muscles, and those that project from the thalamus to the cortex.
• commissural tracts cross from one hemisphere to the other, through the corpus callosum and the anterior commissure.
• association tracts connect regions within the same hemisphere (long ones connect different lobes; short ones connect different gyri within the same lobe).
a synthetic compound similar to marijuana, found to reduce inflammation in older rats and improve their memories.
Working memory capacity. The amount of information you can hold and work with at one time. Now thought to be 3-5 chunks.
- working memory
Working memory contains the information of which you are immediately aware. Information being “put into” memory is held in working memory; memories being remembered are held in working memory. The capacity of working memory — how much information it can hold at one time — is severely limited. Working memory governs your ability to comprehend what you are reading or hearing, your ability to learn new words, your ability to plan and organize yourself, and much more.
Glossary of neurological terms
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