The brain is an organ, like the liver, heart, and kidney, and is made of chemicals, cells, and tissue. Communication between brain cells is mediated through neurons with long processes (axons) that connect many cells at once and release small batches of chemical information (neurotransmitters) to a network of other neurons. The neurons receive the signals on their antennae, called dendrites, which protrude, in many cases, quite elaborately from the cell body. The specific site where the chemical signal from one cell makes contact with another cell is called a synapse, which is made up of

signaling cells Inhibitors,research,lifescience,medical (presynaptic boutons) and receiving cells (postsynaptic spines). The synapse is the Inhibitors,research,lifescience,medical LY411575 structural unit that transmits the majority of information between neurons. Each neuron can have thousands of these synapses on its dendrites and cell body. The real trick for the neuron is to calculate (interpret) the temporal and spatially transmitted information it receives and to send that interpreted message onto the next neurons in a circuit. The aggregation of this information passing and processing results in thought and behavior. Adult neural stability One of the main reasons for viewing the brain as a stable Inhibitors,research,lifescience,medical machine or computer is because this analogy helps explain

how we can remember from one instant to the next. If the underlying structure was changing all the time, how could we do that? For that matter, if the brain is the seat of consciousness, as proposed by Inhibitors,research,lifescience,medical Francis Crick,1 how would we

maintain a self identity if the brain were not stable? Well, the dirty little secret is coming out: the brain is not stable and that is a good thing. The structural changes seen in the brain may be required to provide the extra capacity we need for dealing with complexity. It may also provide the underpinning for the adaptability and flexibility, or “plasticity” as neuroscientists refer to it, that is required for dealing with the variety of challenges that we face throughout life. In addition, and in some ways even more importantly, Inhibitors,research,lifescience,medical structural plasticity provides the mechanism for the brain to repair itself. All organs of the below body have some capacity to repair themselves following minor injury. Skin, liver, heart, kidney, lung, and blood have some level of repair capacity, and most have the capacity to generate new cells to replace damaged ones, at least to a small extent. Until recently, the brain was considered unique in its lack of ability to repair itself once it had matured to adulthood. Researchers were convinced that “Once development was ended, the fonts of growth and regeneration of the axons and dendrites dried up irrevocably. In the adult center the nerve paths are something fixed and immutable, nothing may be regenerated” (S. Ramon y Cajal, 1928).2 This dogma even influenced clinical research and the accepted methods for treating brain damage.