The last four books I've read were all written by doctors - When Breath Becomes Air, Song of the Cell, Being Mortal and Life Lessons from a Brain Surgeon. The reason I gravitate towards books written by doctors, I've realised, is because as an aspiring researcher it’s incredibly motivating to learn about how laboratory endeavours translate into the clinic, hearing compelling stories of research advancements that have tangibly saved human lives.

From the perspective of a researcher, Life Lessons from a Brain Surgeon was inevitably simplified, but Dr Rahul Jandial effectively talks about how theoretical knowledge comes to life, and offers a glimpse into the exciting new frontiers being explored in neurobiology. He delves into the operations of the human brain, dispells misconceptions and outlines actionable strategies to enhance brain function. Thus, this isn’t so much a book review as it is a dive into ideas that struck me as fascinating in the book.

My principal takeaway from the book is that our brain chemistry is what controls our entire body and shapes our individual experiences. Many attributes we consider integral to our identity are actually the result of specific brain chemistry, and this chemistry is malleable.

For instance, Deep Brain Stimulation is a procedure which involves the use of small electrodes implanted in specific regions of the brain to deliver electrical pulses to areas which can modulate the activity of neurons. Dr Jandial talks about how “functions traditionally related to the psyche, such as friendliness, pleasure or verbal expression, can be induced, modified and inhibited by direct electrical stimulation of the brain”. If a specific brain region associated with pleasure or reward is stimulated, it can potentially induce feelings of pleasure or happiness in an individual. Similarly, if a brain region responsible for verbal expression is stimulated, it could enhance or inhibit a person's ability to speak.

A line in the book goes: “Nobody says that a person "has" creativity; we say he or she “is” creative. But let a tumour grow between our frontal lobes and we learn–surprise!– those great gifts were simply on loan”. While the book doesn't extensively explore this subject, the idea that emotions and traits we deem innate could merely be the result of brain chemistry has profound implications for how we perceive human capabilities and existence. This understanding challenges the very notion of 'self'. Defining aspects of a person's identity, such as language ability, can be altered or lost. What we perceive as inherent nature could simply be a matter of brain chemistry, manipulable by medical intervention.

Dr Jandial also talks about mental health as a result of altered brain chemistry. He explains that “depression and anxiety are increasingly being understood in terms of aberrant electrical brain waves”. Our brain's activity is regulated by the synchronised firing of neurons, leading to oscillations at various frequencies. These oscillations, or brain waves, can be measured via an electroencephalogram and are categorised into different types depending on their frequencies: delta, theta, alpha , beta, and gamma. Each of these wave types are associated with different cognitive and conscious states.

In major depressive disorder, studies have shown both hypoactivity and hyperactivity in different brain regions and frequency bands. One particular abnormality often reported in MDD patients is elevated resting-state theta power in the frontal cortex, particularly in the prefrontal and anterior cingulate cortices. This may be associated with a heightened self-focus or rumination commonly observed in depression. On the other hand, alpha asymmetry, where the left frontal cortex shows reduced alpha power compared to the right, has been linked to depressive symptoms as well. Reduced alpha power is usually associated with increased neural activity, so this asymmetry might reflect a dysbalance in emotional processing networks.

In anxiety disorders, there's also evidence for altered neural oscillations. Increased beta activity is commonly reported, possibly reflecting a state of heightened alertness or anxiety. Similarly, aberrant theta and alpha oscillations have been observed.

These findings have large implications on how we view mental health - mental health disorders have a biological basis, and are not merely a result of personal weakness. Moreover, mental health disorders are often diagnosed based on reported symptoms and observable behaviours, which can be subjective. Using brain waves as a diagnostic tool gives a more objective measure to assist in diagnosing mental health disorders.

It also confirms that mental health exists on a spectrum, rather than being a binary (healthy vs. disordered) state. Everyone has variations in their brain wave patterns, and these might relate to variations in mood, cognition, and behaviour. In this view, mental health disorders could be seen as extremes on a spectrum of brain function, rather than entirely separate categories of health.

Another topic Dr Jandial goes into, which I personally find the most exciting, is neural stem cells. The famous Cajal's dogma posits that neurons, unlike other cells in the body, cannot regenerate once they are lost or damaged. However, more recent research has challenged this notion, particularly with the discovery of neural stem cells.

Neural stem cells are cells that have the potential to differentiate into various types of neural cells. This is exciting because NSCs can theoretically replace lost or damaged neurons in case of injury or neurodegeneration, restoring function to affected areas. For instance, in Multiple Sclerosis, NSCs can differentiate into oligodendrocytes, the cells that create myelin sheath around nerve fibres, leading to remyelination.

Of course, neural stem cell therapy is still in a nascent stage. We do not know of its safety, there is always a risk of complications such as infections, or uncontrolled growth leading to tumours. Moreover, for any new cells to be functional, they must integrate correctly into existing neural networks, which is a not fully understood process.