You are what you are is not as simple as it sounds, because who we are is based not just on our identities, but also our dreams, hopes, intelligence, memories, the world around us, and neurobiology. Neurobiology is a branch of biology that studies the development, anatomy, physiology or functioning of the nervous system, with emphasis on how our cells generate and control behaviour. It also corresponds to the co-ordinated management of such cells as functional circuits. Or, how our biology helps us to process information and mediate behaviour. In plain terms, neurobiology is an offshoot of biology and neuroscience. However, it is different from neuroscience — which systematically ‘swots up’ our nervous system, its working, or physiology.
Neurobiology is, in essence, a multifaceted science — it not only examines the development of the brain, or the neurological origin of disease, it also focuses on the molecular structure of the brain and our nervous system, including the configuration and function of the cerebral cortex. It looks at a host of biological factors that impact learning or mood too, besides ‘figuring-out’ early genetic material that develops into several areas of the brain.
Neurobiology, which first emerged in the 1960s, transformed itself as neurobiologists began to study the precise manner in which genes affect the structure of our brain. With the emergence of the Human Genome Project [HGP], the field of neurobiology soared to its higher existence, while deciphering and quantifying the intricate association that exists between specific genes and neurological feedback.
Neurobiology has as much to do with neurons as silicon chips in a computer. Neurons are nerve cells specialised to receive, disseminate or transmit electrochemical impulses. There are over a hundred billion neurons — each as diverse in detail vis-à-vis their structural features and physiological function.
In the initial stages of its development, the human brain is loaded with a glut of unstipulated connections between neurons. When our development and learning expands, the connections are ‘clipped,’ leaving the stronger and more specific neurons. This fine-tuning bids fair to a definitive response — it refines a glut of inputs from our surroundings. Research evidences that this ‘modified’ outcome acts as a ‘go-between’ for changes at synapses. Synapses are like railway junctions — they are specialised neural intersections through which neurons communicate with each other.
Neurons are also endowed with specialised branched projections from the cell body. These are known as dendrites — they not only receive information, but also form synaptic contacts with other nerve cells and allow nerve impulses to be broadcast. This leads to patterns that optimise synaptic interactions. According to a new study, there are complex mechanisms involved in the setting up of such a vast communication network in the brain, what with changes in synaptic connections being controlled by ‘shifts’ in the process and action of each cell. It is evidenced, no less, that such a regulation holds the key in the progression of making proteins, which are essential for long-term changes in synaptic connectivity.
Medical scientists now believe that expanding research in neurobiology holds fresh hope to people suffering from emotional disorders, autism, or other developmental diseases. This is because it holds the prospect of early diagnosis — the reason being one would be able to ‘tap’ and treat abnormal neurological wiring which occurs early in life.
Researchers have identified the protein calcineurin [CaN] that controls synapse formation, action and function. CaN has been implicated in ‘snappy’ connections between cells. This has led to the development of a technique that specifically blocks the interaction between CaN and other cell factors at the nucleus. This also, in effect, is evidenced to analyse the effects of neuronal connections in the visual system. Researchers say that inhibiting such a CaN function results in more dendritic branches and synapses.
As new insights emerge with regard to how neurons control the growth of intricate branches of dendrites, researchers are confident that this could soon help them to better understand brain development. This would, in effect, enable them to also treat and restore neuronal connections lost due to brain injury, stroke or neurodegenerative disorders.
New research also suggests that structures called ‘Golgi outposts’ play a crucial role as distribution points for proteins. Proteins, as you already know, are building blocks of emergent dendrites. The Golgi apparatus is a cellular depot. It is responsible for receiving, cataloguing and transporting the cargo of newly synthesised molecules needed for cell growth and function. It was earlier believed that only a central Golgi apparatus played a key role in such allocation, but not anymore. Golgi has a typecast composition, a loaded system housed near the cell nucleus. While neurons in our brain are vast, with a surface area about ten thousand times that of average cell, it is, indeed, a big question as to where all the membrane components emerge from to ‘spawn’ the composite surface of growing dendrites. Recent research has found a plausible answer — that such distant structures in dendrites, called the Golgi outposts, hold a decisive responsibility.
New studies have, likewise, shown that the Golgi outposts are prone to materialise in longer dendrites, including Golgi in the main cell body that becomes acquainted with longer dendrites. Studies suggest that growing dendrites are homogeneous in length; they also grow at a consistent rate. However, when the Golgi traverses towards one dendrite, it grows animatedly to emerge as the longest dendrite, while establishing itself at ‘preferred’ dendritic branch points.
It is obvious that new, emerging studies will delve into the nitty-gritty of Golgi outposts — of how they arrive at dendritic branch points and what consignment they dispense. The outcome of such studies could offer significant evidence into the mechanism, regulation and control of neuronal growth. The upside of such research endeavours is imminent — it would not only establish, but also provide a clinical bearing on brain development disorders, which present or manifest with abnormal dendritic structures.
It is established that most neurodegenerative disorders, including Parkinson's and Alzheimer's diseases, are outcomes of flawed protein processing. The downside is we do not know, as yet, as to how and where integral membrane proteins are synthesised and processed by neurons. Once this happens, it will be the embodiment of reaching the next level — in terms of managing brain disorders with better, clinically safe and effective therapeutic outcomes.
It’d be exciting, in the context, to know that researchers in Sweden have embarked on the first artificial nerve cell device which communicates with nerves in their ‘own language of neurotransmitter chemicals,’ not electrical impulses. The new device employs the same neurotransmitters that natural nerves use. It allows the ‘robotic’ nerve to target specific neural pathways, without the haphazard side-effects of electronic neural stimulation. While the technology is still in its formative avatar, medical scientists are cock-a-hoop with the electrifying potential it holds to bring about a paradigm shift in brain-electronics interaction. Once the device reaches ‘critical mass,’ it is expected to release neurotransmitters needed to regulate uncontrollable nerve ‘firings’ associated with brain disorders, including schizophrenia.
The next big leap would be just as exhilarating — as artificial nerve cell technology becomes smaller and affordable, ‘synthetic’ nerves could be used to create bionic brain prostheses for brain injury and stroke victims. It’d also be, with good effect, employed as a ‘go-between’ biological brains and electronic computer systems — a roseate apotheosis for medicine and technological advance.