2nd writing

Just a quick update to say the next thing I will be writing about is synaptic/neural plasticity. It is an interesting topic and explains so much about how networks form, how we learn and memorise everything, why somethings are more painful than others and it seems to be the underlying mechanism involved in correct brain function. I will be using memory as the main example but will refer to pain. I will not use pain too much because I want to cover pain as a separate post. gene expression is heavily implicated in long term potentiation which may sound boring but I promise that when it relates to the most important underlying mechanism in the brain, it becomes a lot more interesting (if you're as nerdy as me you might even go so far as to say exciting).

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An overview of the brain

This is just a short writing being as it is my first.

I don't want to dive into the world of neuroscience without first covering an overview of the most important aspect, the brain. Your brain is the most sophisticated organic model to exist, arguably the most sophisticated of anything to ever exist, and the human brain is the most advanced of any brain. 

The brain consists of neurons and glial cells. Neurons are the chief signalling cells in the body, they signal locally in the brain, or to the spinal cord or to everywhere in the body for every reason conceivable. Glial cells have been seen as just accessory cells for many years despite the fact they outnumber neurons by at least 10-1 and potentially 50-1. Given that there are around 100 billion neurons in an adult brain, it is impossible to think that scientists just assumed that between 1 and 5 trillion cells in one organ just did nothing important. You'll be happy to know that now we are starting to learn what they do, some of them work with neurons by helping to produce neurotransmitters or precursors and plenty of other things. These glial are called astrocytes  and a textbook example of this partnership are glutamate neurons and the accompanying astrocytes, when the neurons release glutamate to the synaptic cleft it acts on the postsynapic neuron. This is a signal and this signal needs to be regulated because this synapse could be one controlling a motor neuron in the hand, the excessive signalling may cause a tremor. So astrocytes contain channels that allow glutamate to enter, the astrocytes then converts it to glutamine via glutamine synthetase. The glutamine is then released from the astrocyte to the neuron again that will then convert the glutamine to glutamate. Other forms of glial cells exist and will be focused on in a later post along with types of neurons and their locations.

www.interactive-biology.com%2F3247%2Fthe-neuron-external-structure-and-classification%2F&bvm=bv.128153897,d.d24&psig=AFQjCNHBNv0q7V9MAZtFbthcRltPeLEnyA&ust=1469744123179382 

The gross anatomy of the brain is built of the neurons and glia that have been mentioned which combine to form this structure that is literally somehow split into different sections depending on the neurons role that are present. such that there is a section that only deals with vision and within this section there are subsections that control specific aspects of vision. Amazingly these sections all have 6 layers as identified by Brodmann, the Lemmy Kilmister of neuroscience. the visual cortex is not a perfect example of this because there are sub-layers too but for the most part Brodmann was spot on with his discovery of 6 layers in the neocortex. These layers are identified by the type of neuron in it and what it does, for example layer 4 has sensory neuron input whereas layer 6 receives input exclusively from the brainstem.

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The final part of this quick overview is just covering the main divisions of the brain, there is the boring stuff like telencephalon, mesencephalon and rhombencephalon but I am going to focus quickly on the lobes and the main areas to look out for in those lobes.

www.hearingcareuk.com%2Fnews%2Fbrain-area-identified-that-determines-distance-from-which-sound-originates%2F&bvm=bv.128153897,d.d24&psig=AFQjCNEDNQNYDK5TejpxM_kCFXbIafD_Qg&ust=1469745977364335

The blue is the frontal lobe, this is seen as the area that is most different and most advanced in humans compared to any other animal, it is almost non-existent in most animals. Here is where the motor area for speech is located, this is why humans can speak, however the area that understands language is in the temporal lobe which is present in many animals, this is why animals can understand commands from humans but cannot speak. The frontal cortex also contains the motor cortex but it is in the precentral gyrus, part of the frontal lobe. It is responsible for all motor movement, in case that wasn't obvious. 

The temporal lobe contains parts of the auditory cortex and importantly, deep inside it as you cut it the hippocampus appears, the area controlling short term memory and the limbic system can be found (i'll cover this another time). 

The occipital lobe almost exclusively vision associated (purple) and just above is the parietal lobe which is important as it contains the somatosensory cortex which basically takes inputs from anything from your environment: touch, vibration, pressure and pain.  

The cerebellum is the brown area at the back and is motor control in the sense that it adjusts movements and acts as a motor brain keeping movement memory for all movement. 

The final area is the brainstem, consisting of the midbrain and the hindbrain mainly controls systems needed for survival and basic instincts 

The last thing I am going to point out is that the diagram labelling two areas as association cortices, ignore this, 70% of the neocortex (not brainstem or cerebellum) are association cortices that interact with other association areas and the primary cortices and with the other hemisphere. 

I hope this was slightly interesting. If anyone actually reads this blog ever it will get more interesting as more interesting topics are discussed but the basics have to be pointed out before that can happen. 

(This writing hasn't been fully checked because it is 12:45 am) 

Thanks

F

Intro

Out of term time I can struggle to get into the routine of getting some work done in the form of reading papers. So this blog is partly set up to give me a reason to work and partly to bring people who are interested in science and students something to read that isn't insanely specific about one thing that leaves you questioning what is even going on.