Free The Root of Thought by Andrew Koob

other astrocytes. It is now known that the end feet of different astrocytes wrap around each other and form a junction through which receptors bind the two cells.
    Gap junctions are present in other types of organs as well, such as the liver and the heart. Gap junctions are fused together by intracellular channels. Imagine a lock and a dam. The water level on one side is higher than another, but a free exchange of barges and boats occurs in the lock where water levels can be raised or lowered to the other side’s level. The regulated lock and dam of the astrocyte gap junction determines what can pass from cell to cell.
    About 230 gap junctions connect a pair of astrocytes in the cortex. If a dye is injected into one astrocyte, 50–100 neighboring astrocytes will be stained with the dye. In different brain regions, the degree of astrocyte cell-to-cell connection differs. Almost all cortical astrocytes are physically connected, as Golgi suspected for a cell responsible for thought.
    Oligodendrocytes, the cells that wrap insulation around axons to better help neurons conduct electricity, also form gap junctions with astrocytes. Although they are not as efficient as astrocytes when conducting to each other, astrocyte gap junctions with oligodendroctyes might be a way to control myelination to increase conductance in neurons. This analogy can be better explained if one considers the oligodendrocytes as construction workers that work on the neural road. Astrocytes send an orderto fix the road because cars aren’t moving as fast as they’d like down the freeway.
    In fact, in development of neurons, gap junctions can exist between astrocytes and neurons. These gap junctions can be understood as the building of a new road between astrocyte centers in the cortex—the architect and city planner building new infrastructure.
    The main internal complexes where astrocytes store calcium are called the endoplasmic reticulum, mitochondria, and Golgi complex (named after the same Golgi, who noticed the structure in his stained cells in the late nineteenth century). These compartments are surrounded by membranes and have their own electrical gradient between the rest of the intracellular space of the cell. Because these compartments also exist in the intracellular space, the intracellular space outside these compartments is confusingly referred to as the cytosol.
    The other paper from Yale, by Steven Finkbeiner in 1992, explained a series of experiments where they loaded dye into the astrocytes that attach to calcium. The visualized movement of calcium waves from one cell to the next occurs in a curvilinear pattern. One cell stimulates the next like a series of dominoes in patterns similar to the Milky Way.
    Finkbeiner’s research blocked inositol triphosphate and was able to stop the flow of the calcium wave from one cell to the next.
    It should be said here that inositol triphosphate is a painful and boring name concocted by chemists accoding to their naming system. It is not a protein or gene, but a molecule. For what it’s worth, inositol means it has 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms. The triphosphate means that three phosphate groups are attached. Some of the worst names in the history of science have come about as we enter the era of biology concerned with genes and proteins. We are subjected to the uniform naming of these poor structures, an idea that usually backfires as researchers realize the protein doesn’t do what they originally thought it did. A special place is in everyone’s heart for the guys that discovered a protein in the early 1990s and named it Sonic Hedge Hog after the Sega video game they were playing at the time. Even better is that it turned out to be incredibly important in embryonic development. There’s nothing more enjoyable than taking a class in biology taught by a difficult professor who is forced to say Sonic Hedge Hog 30 times in 15 minutes.
    As it became known that calcium could