How the brain stores information: Enigma of Synaptic transmission ! Brain series article #5

Information is a compilation of the facts that you come across or learn. Obviously, we remember a number of things, that we have experienced or learned or come across; but do you know how the brain stores all the information? Well, it is because of these tiny yet mighty little junctions throughout the brain that are responsible for the same. Today, let’s get to know how ‘synapses’ store information in the brain.

In the labyrinth of the human brain, where billions of neurons intertwine in a complex network of connectivity, lies the secret to how information is held, processed, and remembered. At the heart of this neural symphony are synapses – tiny but mighty junctions that serve as the fundamental units of communication between neurons. Understanding how information is stored at synapses is not only a cornerstone of neuroscience but also sheds light on the essence of cognition and memory.

The synapse dance:

Synapses are the bustling hubs where neurons exchange information, akin to bustling marketplaces where goods are traded. When an electrical signal, known as an action potential, reaches the end of a neuron's axon, it triggers the release of neurotransmitter molecules into the synaptic cleft, which is a microscopic gap between the sending neuron (known as the presynaptic neuron) and the receiving neuron (known as the postsynaptic neuron). These neurotransmitters diffuse across the synaptic cleft and bind to receptor sites on the membrane of the postsynaptic neuron. In this molecular dance, neurotransmitters act as messengers, conveying signals from one neuron to another. Various types of neurotransmitters exist, each with its own specific receptors on the postsynaptic neuron. This specificity allows for precise communication within the brain, akin to different languages spoken in different regions of the world.

When these neurotransmitters connect with the next cell, they trigger a chain reaction. It's like flipping switches that let tiny charged particles flow in and out of the cell, changing its electrical charge. This change is like a message that tells the cell to do something. All these messages from different cells come together in one cell. If enough of them say the same thing, it sets off a big electrical burst, like a signal traveling down a wire. This burst keeps the message going to other cells.

Why do we remember some things and forget the rest?

The strength of synaptic connections is not fixed but subject to modification over time, a phenomenon known as synaptic plasticity. Through mechanisms such as long-term potentiation (LTP) and long-term depression (LTD), synapses can become stronger or weaker in response to patterns of activity. This plasticity underlies learning and memory formation, allowing the brain to adapt and encode experiences. This synaptic plasticity is based on the way your subconscious mind responds to everything. For instance, if there is a memory that is of utmost importance or very special for you, your synapses at the time of the first experience of this memory will hold onto it tightly, using LTD. Whereas in case of a memory you wish to forget, your subconscious mind will order the synapses to forget those, using LTD. 

Concluding the article, in the vast expanse of the brain, synapses stand as the gatekeepers of information, orchestrating the intricate dance of neural communication. Through their remarkable ability to transmit, integrate, and adapt signals, synapses serve as the foundation of cognition, memory, and learning. As we continue to probe the mysteries of synaptic transmission, we inch closer to unraveling the enigma of the human mind. 

The best part about our brain is that while writing this, my synapses are using the LTP mechanism to enlighten y’all with this information, whereas your synapses are deciding whether to go ahead for LTP or LTD! Irrespective of it, I hope now you know the reason behind your brain remembering information and storing it.

Thanks for reading!

- Rachna Jadhav

@theresilientresearcher