A Distributed Ledger

The Ethereum network is an instantiation of Distributed Ledger Technology (DLT). Distributed Ledgers confer many advantages over Centralized Ledgers, and many are the by-product of Decentralization.

Some of these benefits include:

• Permission-less Nature

• Censorship Resistance

• No Single Points of Failure

• Trust Minimization

From a Game Theory perspective, incentives align favorably such that the governing dynamics motivate each participant in these systems to maximize outcomes for oneself and the network at large. As a result the network reliably serves the purposes of storing, sharing, synchronizing, and replicating information across all nodes throughout the system with one overarching aim: achieving consensus.

Ethereum Virtual Machine

On Ethereum information is continually encoded within the distributed ledger, as every transaction hash is permanently – immutably – logged onto the chain of blocks where history is recorded. Transactions are computations that are often combined into a series of if-then statements known as Smart Contracts, and these Smart Contracts are executed inside the Ethereum Virtual Machine. This is how decentralized applications (dApps) operate without the need for any centralized trusted parties.

Every transaction on the Ethereum network results in the creation of Gas, which is used to execute smart contracts. This is a key distinction of Ethereum in comparison the Bitcoin, which was the first network to enable peer-to-peer exchanges of value but did not execute smart contracts.

1) Ethereum Transaction from one node/software client to another. 2) Miner secures transactions in a block by mining the block reward, and transactions are immutably added to the distributed ledger. 3) Miners are additionally compensated with Gas fees for their help in securing the ledger. 4) Gas is also used for computations within the Ethereum Virtual Machine (EVM).

Neuronal "Virtual Machine"

This framework can be applied to the brain: as information is continuously transmitted along neurons, it is also being integrated, amplified, encoded, and stored within.

1) Action Potential travels down axon of the pre-synaptic neuron. 2) This triggers the release of vesicles that contain Neurotransmitters. 3) Neurotransmitters flow across the synapse to transmit/transact information. 4) Action Potential can be triggered in the post-synaptic neuron. 5) Signal is amplified through second messenger cascades by putting Fee Energy to work – this process is similar to Gas used for computations in the EVM.

Signal amplification proceeds through second messenger cascade systems:

After a neurotransmitter (signal) binds to a receptor, the information is transduced intra-cellularly through cascades. Free energy minimization is yet again exemplified, as every step is coupled to another: signal (NT) binding to receptor --> signal transduction --> Primary effector --> Second messenger, and so forth.

Much like Gas created in the Ethereum Virtual Machine (EVM) is used for executing smart contracts, the Free Energy from neuronal transactions is minimized and redirected towards cascading downstream “applications."

These signals are transduced by enzymes, and they have key regulatory roles in nearly all cells.

E.g. Adenylyl Cyclase catalyzes the conversion of ATP (Adenosine Triphosphate; a ubiquitous compound which provides energy to drive many cellular processes) to cAMP (cyclic adenosine monophosphate; another enzyme that is used to shuffle around ATP).

The signal is amplified, distributed through the cell, and transduced all the way to the nucleus where DNA resides.

Both systems are executing logic.

Why might the message be relayed to the core of the neuron, inside the nucleus?

Because this is where the database - the Ledger - of our Genome is found.

The genome contains all genetic material of an organism, stored in the form of Deoxyribonucleic acid (DNA). Every cell in the body contains a copy of this database.

While the DNA itself is static and largely unmodifiable, the expression of DNA is fluid. This enables cells to specialize into types such as epithelium, vascular endothelium, osteocytes, etc.; and neurons.

The nucleotide base pairs comprising the DNA sequence (ledger) are rarely altered, but DNA expression is modulated through processes like DNA methylation and histone modifications. These are termed Epigenetic changes:

DNA methylation and histone modifications influence (in)activation of DNA, and subsequently RNA transcription and/or protein synthesis translations.

Epigenetic changes have profound impacts on human behavior:

E.g., Heightened hypothalamic-pituitary-adrenal (HPA) axis stress reactivity is seen in children prenatally exposed to depressed and anxious mood experienced by the mother, as a result of increased DNA methylation at the glucocorticoid receptor gene.

Epigenetics can influence the emergence of nearly every psychiatric disorder, and even our momentary mental states – to the extent that they are perceptible.

An Analogy

Applying what we've covered so far, we can conceive the following.

Bitcoin is similar to the sugar-phosphate backbone structure and base pairs of DNA; it is static and very slowly (if at all) changing. The purpose of the Bitcoin distributed ledger is to securely store a ledger of value transacted in the form of Bitcoin.

On the other hand, Ethereum is a state machine which changes dynamically from block to block. Ethereum more closely resembles the ecosystem around the static DNA, as it is a more fluid and nimble structure. Enzymes such as DNA polymerase are kind of like dApps; there is literally a project on Ethereum called “Enzyme,” previously known as Melon protocol.

In essence, Bitcoin is a distributed ledger aiming for security and ossification. Ethereum is a distributed state machine. Both networks add new blocks to their respective blockchains to update the record of transactions.

In contrast, the brain’s distributed ledger has no blocks. Instead, information is perpetually transduced intra-cellularly through cascades and converted into epigenetic changes.

Neurons = Block Space

The entire neuron can be conceptualized as a data storing block on the nervous system distributed ledger; because in addition to the changes described above, signal transduction is continuously modifying the structure of neurons. This is evident in observations such as microtubules altering neuronal cytoskeleton down the length of axons, and the number of synaptic receptors dynamically adjusting to supply and demand information conveyed by neurotransmitters.

This is the basis for Neuroplasticity:

This enables the brain to achieve a state of consensus.