Quote from: Donald
What fail-safes did evolution manifest?The harshest fail-safe is that an animal which has regular seizures is more likely to become lunch.
At the electrical level, neurons are affected by signals that encourage firing, and those that inhibit firing. This is a complex, non-linear system which can sometimes exhibit cyclic and/or chaotic behavior - especially if an injury or stroke damages the normal circuitry.
This abnormal electrical behavior is not just restricted to the brain - similar faulty circuits in the heart can result in arrhythmia or fibrillation - which can be fatal.
The brain can't tell the impulses are coming from an injured cell vs a healthy one.An injured cell is more likely to die, and produce no impulses.
It is estimated that about 1 adult in 8 suffers from tinnitus, which is caused by damage to the inner ear, causing cells in the cochlear to misfire, producing spurious signals in the brain which are interpreted as sound.
Most people manage to ignore it to some extent - but for others it can be quite debilitating.
Tinnitus is a case where the spurious signals are mostly restricted to the auditory section of the brain, disabling one sense, but leaving muscle control unaffected.
However, in epilepsy, the spurious signals spread out to involve large sections of the brain, causing loss of consciousness and convulsions or rigidity. In extreme cases, surgeons have separated the left and right side of the brain by severing the corpus callosum, in an attempt to prevent these electrical storms spreading from one side of the brain to the other.
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