Whether judged in molecular, cellu­lar, systemic, be­havioural, or cognitive terms, the human nervous system is a stupendous piece of biologi­cal machinery.

Given its accomplish­ments—all the artifacts of human culture, for instance— there is good reason for wanting to understand how the brain and the rest of the nervous system work.

The debilitating and costly effects of neurological and psychiatric disease add a further sense of urgency to this quest. The aim of this concept of Emotional Surgery is to highlight the intellectual challenges and excitements— as well as the uncertainties— of what many see as the last great frontier of biological science.

The information presented should serve as a benchmark for professionals in Neurosci­ences, and others who want to understand how the human nervous system operates. Like any other great chal­lenge, neuroscience should be, and is, full of debate, dissension, and considerable fun.

The human brain contains more than 100 billion neu­rons. Just like a single ant can never build an ant hill a single neuron cannot think, feel or remember. A neu­ron’s power is a result of its connections to other neurons. Each neuron is connected to as many as millions of its neighbours.

These trillions of connec­tions provide the playing field upon which complex activi­ties of the brain takes place. Each neuron can turn its neighbour on or off depend­ing on the signal it sends. And the resulting stable patterns of neurons firing repre­sent memories, images and thoughts.

We do not yet understand the relationship between neuron activity and mental experience. We do not know what the precise pattern of memory or image or thought looks like.

The absolute truth is this, that the shorter your sleep, the shorter your life. The decimation and fragmenta­tion of sleep hours through­out industrialised nations including developing nations is having a lethal catastrophic stealth impact on our health, our wellness, even the safety and the education of our children.

It is a silent sleep loss epidemic, and it is swiftly becoming one of the greatest public health challenges that we face in the 21st centu­ry. The disruption of deep sleep is an underappreciated factor that is contributing to cognitive decline or memory decline in aging, and most re­cently we have discovered, in Alzheimer’s disease as well.

What is beta-amyloid? Be­ta-amyloid is a small piece of a larger protein called “amy­loid precursor protein” (APP). Although scientists have not yet determined APP’s normal function, they have learned a great deal about how it appears to work.

In its complete form, APP extends from the inside to the outside of brain cells by passing through a fatty mem­brane around the cell. When APP is “activated” to do its normal job, it is cut by other proteins into smaller sections that stay inside and outside cells. There are several dif­ferent ways APP can be cut. Under some circumstances, one of the pieces produced is beta-amyloid.

Why is beta-amyloid a prime suspect in Alzheimer’s disease?

Beta-amyloid is chemically “stickier” than other frag­ments produced when APP is cut. It accumulates by stages into microscopic amyloid plaques that are considered one hallmark of the Alzhei­mer brain.

The pieces first form small clusters called oligomers, then chains of clusters called fibrils, then “mats” of fibrils called beta-sheets. The final stage is plaques, which contain clumps of beta-sheets and other substances.

According to the amyloid hypothesis, these stages of beta-amyloid aggregation disrupt brain cells by clogging points of cell-to-cell commu­nication, activating immune cells that trigger inflamma­tion and devour disabled cells, and, ultimately, killing cells.

By Robert Ekow Grimmond-Thompson