Brain Trees

Hey team,

Over the past 2 weeks or so I've been reading the book "Trees of the Brain, Roots of the Mind" by Giorgio A Ascoli. I always just refer to it as "brain trees" hence the name of today's post. The book is about 200 pages and for a book that short, I learned a lot about neurons (the cells of the brain and nervous tissue). I'd like to briefly go over some of the information I've come to understand and greatly appreciate. 

The book serves to present some major principles of neuroscience and the mind-brain connection. One of the principles is that unique mental states correspond to the subjective experience going on in our heads, both what we are aware of (ex. talking, eating) and the kind of stuff going on in our heads that we aren't fully aware of (ex. short-term memories being transferred into longer-term storage). Any memory, any feeling, and any moment can all come down to a specific and unique mental state. But what is a mental state? A mental state is the specific electrical/ neural activity in your brain corresponding to the spikes of electrical firing from one neuron to the next and to the next. As I've written about in previous posts, neurons utilize both electrical and chemical signaling to transmit information (and to process it on a larger scale). These unique mental states are the result of a brain that has been shaped and transformed over a lifetime of living. Every time we learn something new through experience our brain changes, hence why before we didn't know something, and now we do. Through learning we gain knowledge, and knowledge is the ability to access specific mental states corresponding to coordinated patterns of specific neuron activity. Through learning and gaining knowledge, whether the memories of walking in a forest or learning about how antibiotics work, your brain has changed and rewired (to a small extent). And the thing about learning is that knowledge is gatekept, as in you can't learn what a water bottle is until you learn what water and bottles are, you can't learn about calculus until you've learned algebra, etc. And this can be seen in the brain as well. As you learn certain information, it primes your brain to learn the next information. In the brain, this manifests as neurons encoding information for the sound of a buzz and other neurons encoding for recognizing a bee. When you see and hear a bee go buzzing by, all the neurons involved for both "buzzing" and "bee" work together and in sync. This collaboration results in the creation of the mental state corresponding to a "buzzing bee". Now at first the connection between all these neurons will be weak and it still might be difficult to recognize a buzzing bee, however as you have more experience with this buzzing bee those neurons will activate repeatedly together and get stronger and stronger. This is the basis of learning and why it often takes several repetitions. The more you activate/ access a specific mental state the easier it is for your brain to access it again(not learning new information but strengthening existing information, increased in probability instead of creating new possibilities). 

This information is stored between neurons in synapses (it's never just one neuron that encodes for a specific fact). Expanding on these synapses and the probability of firing, I’d like to discuss synaptic weight. Synaptic weight is influenced by various factors, one of which is the density of receptors on the postsynaptic membrane (the sheer number of receptors, with more receptors indicating a stronger connection). This increased receptor density enhances the sensitivity of the synapse, making it more effective at transmitting signals.  Receptors are predominantly located on dendrites which come out from the center of the neuron and branch continuously getting thinner and more broad which each branch, quite analogous to the way branches upon branches come out of the main body of a tree. 

The distance between the receptor and the soma (the center/ cell body of a neuron) also plays a role in synaptic weight where synapses closer to the soma can exert greater influence over the neuron's activity because the electrical signals generated in the dendrites must travel a shorter distance to reach the soma. Imagine how the same noise closer to your ears is louder and more easily heard in comparison if the same noise was farther away. Synapses and receptors are the same way. This distance-dependent attenuation of synaptic signals is due to passive electrical properties of the dendrites, such as membrane resistance and capacitance, which can cause signal degradation over long distances.

Also in neurons, specific dendrites are dendritic spines which are small protrusions found on the surface of dendrites. Each spine typically contains receptors, making them crucial sites for synaptic transmission and plasticity.

The presence of dendritic spines can affect the ease of signal transduction at synapses. Spines take in and process synaptic inputs, allowing for localized and efficient signal processing. Additionally, the morphology of dendritic spines, including their size and shape, can influence synaptic strength. Larger spines with more surface area may accommodate a higher density of receptors, leading to stronger synaptic connections.

Furthermore, dendritic spines provide structural support for synapses and help regulate the flow of ions and signaling molecules, thereby influencing synaptic plasticity. Changes in spine morphology, such as spine enlargement or shrinkage, are associated with synaptic potentiation (strengthening) or depression (weakening), respectively, contributing to the dynamic nature of synaptic weights. My point in describing all this is to emphasize the beautifully elaborate and dynamic process of Hey team,

Over the past couple of weeks, I've been reading the book "Trees of the Brain, Roots of the Mind" by Giorgio A Ascoli. I have been referring to it as "brain trees". In just 200 pages, I have learned a lot about neurons and the cells of the brain and nervous tissue. I want to share some of the information I have come across that I find fascinating.

The book aims to present some major principles of neuroscience and the mind-brain connection. One of the principles is that unique mental states correspond to the subjective experience going on in our heads, both what we are aware of (ex. talking, eating) and the kind of stuff going on in our heads that we aren't fully aware of (ex. short-term memories being transferred into longer-term storage). Any memory, any feeling, and any moment can all come down to a specific and unique mental state.

But what is a mental state? A mental state is the specific electrical/ neural activity in your brain corresponding to the spikes of electrical firing from one neuron to the next and to the next. As I've written about in previous posts, neurons utilize both electrical and chemical signaling to transmit information (and to process it on a larger scale). These unique mental states are the result of a brain that has been shaped and transformed over a lifetime of living. Every time we learn something new through experience our brain changes, hence why before we didn't know something, and now we do.

Through learning, we gain knowledge, and knowledge is the ability to access specific mental states corresponding to coordinated patterns of specific neuron activity. As you learn certain information, it primes your brain to learn the next information. The more you activate/access a specific mental state, the easier it is for your brain to access it again. This is the basis of learning and why it often takes several repetitions.

This information is stored between neurons in synapses. Expanding on these synapses and the probability of firing, I’d like to discuss synaptic weight. Synaptic weight is influenced by various factors, one of which is the density of receptors on the postsynaptic membrane (the sheer number of receptors, with more receptors indicating a stronger connection). This increased receptor density enhances the sensitivity of the synapse, making it more effective at transmitting signals.

The distance between the receptor and the soma (the center/ cell body of a neuron) also plays a role in synaptic weight where synapses closer to the soma can exert greater influence over the neuron's activity because the electrical signals generated in the dendrites must travel a shorter distance to reach the soma. 

Also in neurons, specific dendrites are dendritic spines which are small protrusions found on the surface of dendrites. Each spine typically contains receptors, making them crucial sites for synaptic transmission and plasticity. The presence of dendritic spines can affect the ease of signal transduction at synapses. Spines take in and process synaptic inputs, allowing for localized and efficient signal processing.

Through reading  "Trees of the Brain, Roots of the Mind" I have gained the ability to access specific mental states corresponding to neural activity encoding information regarding the principles of neuroscience and the mind-brain connection which I have shared with you all today. Learning something new, our brain changes, and we gain knowledge. This knowledge is stored between neurons at synapses, and the synaptic weight is influenced by various factors. The presence of dendritic spines can affect the ease of signal transduction at synapses, allowing for localized and efficient signal processing, neuronal signaling and plasticity. 

Neuron looking like a whole ass tree.