The human brain is arguably the most complex organ. Throughout life, it is shaped ever so slightly by each and every experience we endure. The resulting nuances are what make us unique individuals. Unfortunately, the more intricate the system, the harder it is to fix when damaged. Death of any brain tissue will almost certainly result in some sort of physical or cognitive impairment, and, in severe cases, epilepsy, coma, or death. This is because the lost brain tissue can neither grow back like skin nor be replaced like a kidney.
Or can it?
In Dante’s Inferno, the fifth circle of Hell is a place where the wrathful fight each other for eternity. Similarly, I often consider YouTube comments to be an extracanonical circle of Hell where the trolls fight each other for eternity. You might, then, imagine my surprise when I found many thoughtful comments expressing wonder and intrigue on a YouTube video of brain activity in a zebrafish. Continue reading
Unlike the sense of vision, which is perceived only by light-sensitive photoreceptors in our eyes, the mechanoreceptors that respond to light touch are located in sensory neurons all over the body. Our sense of touch starts in the skin, where sensory neurons with elaborate dendrites just below the skin’s surface provide dense coverage over the entire area of the body. When we touch something, the mechanical pressure created by the contact between an object and our skin opens mechanoreceptors that cause the sensory neuron to fire an action potential and activate downstream neurons. We are constantly coming into physical contact with objects and people in our environment, and as a result a large number sensory neurons are being activated over many different areas of our body at any given moment! How does the nervous system handle all of this incoming tactile information?Continue reading