Neurogenesis

Neuroscience (also called neurobiology) is the subdivision of psychology, as well as biology, dealing with the brain. Neuroanatomy is fascinating, but a complicated subject, indeed. In fact, the brain has been designated by neuroscientists as the most complex object in the world. Notwithstanding, goals of science include to explain, so…

The Brain at a Glance

The basic building bloc of the brain is the neuron or brain cell. Neural cells contain a cell body or soma, a myelinated axon (myelin is a fatty substance coating the axon, faciliating and speeding up transmission between neurons), button terminals and dendrites. Neurons are the messengers of the brain and ensure communication in the brain and the rest of the organism by release, absorption and reuptake mechanisms evolving in synaptic clefts (synapses are the space between neurons). Neural influence can be excitatory and inhibitory, and different neurotransmitters bring about diverse results. The main neurotransmitters comprise serotonin, dopamine, adrenaline, epinephrine and GABA.

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brain

Photo : Megan Jorgensen

The brain consists of two hemispheres (left and right) and four lobes (frontal, occipital, temporal and parietal). Three layers, the meninges, insulate the brain, under the rigid skull bone. Cerebral matter may be white (nerve endings) or grey (nerves). The corpus collossum is the main commissure separating the left from the right hemispheres. Interestingly, this fact was established through lesion studies with persons undergoing surgery for epilepsia. Indeed, a lot of neuroscientific and psychological evidence comes from cases, like the famous patient H.M. and the associated research on memory and the hippocampus. Laterality of function remains somewhat debated, but largely the left side has a more analytical and logical specialization, while the right one tends to be more abstract and artistic in orientation.

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Similarly, numerous accounts in the literature provide correlations between neural substrates and behavioral, or emotional, reactions. As such, the amygdala has been linked to fear, anxiety and aversive emotional memories, the hyppocampus to memory and particularly spatial memory, the frontal lobe to executive function (planning, organizing, inhibition/self-control, decion-making), the occipital lobe to vision, the temporal lobe to hearing and so on…

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Neurogenesis

Most teenagers in the West have at some point in their lives heard the expression: Don't do drugs/Watch too much TV/Play too many video games/Drink alcohol - it kills brain cells. As it turns out, to an extent that may be plausible. For instance, a study on creativity published in British Columbia, Canada focused on creativity in youth in a small rural village both before and after modern media and telecommunications were introduced. Not surprisingly to outdoors protagonists, creativity went down. Further, psychology and biology professors do often stress the likelihood of chemical substances, especially substance abuse and dependence, to harm brain cells, but there's more…

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Apparently, depression, or more specifically Major Depressive Disorder and the accompanying serotonin (mood stabilizing neurotransmitter) depletion also destroys neural clusters. Alternatively, neurogenesis refers to birth of neurons, once when the cerebrum is formed (most die per design through natural, biological mechanisms such as pruning and apoptosis); and, in some cases later in adulthood (i.e. a study has demonstrated hyppocampal neurogenesis in laboratory mice who were put on an exercise regimen). In contrast, neuroplasticity relates to the ability and tendance of neurons to rearrange their functionality according to learned processes. Regardless, neuroplasticity is far beyond the scope of the present short paper.

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Psychology, although to a lesser extent neuroscience or neurobiology, have been criticized as social sciences, and thus not exact as, hard or pure and applied science. While the criticism certainly carries weight, rigorous, scientific approaches remain possible with appropriate research methodology - which is why most peer-reviewed articles in academic journals include a methods section, for other researchers to be able to understand and replicate obtained results. Along these lines, unlike physics and chemistry operating in the real world, behavioral phenomena is often best observed in laboratories, with carefully crafted experimental designs and animal models.

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