UniVerses

Death of Ideas

An impulse connects neurons in a synapse
when sacs of neurotransmitters disgorge
from plasma membranes and diffuse across the gaps
and fire receptors, thus the contact’s forged.
The flux of membranes powers nervous cells.
where proteins weave, the bilayers intermesh
their helices like zippers meld micelles.
When done, enzymes uncoil and stretch.
The mind’s a dynamo of membrane fusion
unnumbered proteins twist, unclench and twirl
producing psyche, thought, illusion.
‘Til oxidation causes one to kink, misfurl.
which triggers other proteins to form tangles.
Thus genius’ prey to cytotoxic mangles.

The mind is an amazing machine, but it is a machine. The main activity the mind engages in is neurotransmission, which involves vesicles constantly fusing and budding off from the membranes that surround neurons.

The motors of this membrane activity are specialized proteins which act like zippers. These proteins  have multiple coils that fit together much like the two halves of a zipper merge, drawing the two membranes together until they fuse (or separate).

Proteins that perform this activity are highly complex because they have to change their shape, depending on which part of the cycle they  are in (fusion, uncoiling or pinching off).

The power to change shape makes them vulnerable. Should these proteins misfold, assuming a shape that is dysfunctional, they can serve as a template upon which other proteins will stick. The result can be catastrophic as more and more proteins reorganize into dysfunctional shapes, creating aggregates that, literally, gum up the works. These tangles are insoluble and eventually kill the neurons. Depending on where in the brain they occur, the disease they cause is called Parkinson's, Alzheimer's or other less common neurodegenerative diseases.

The brain is uniquely susceptible to this type of disease because it is full of these types of proteins.

Thus the machinery of the mind consists of electrical impulses within cells which are connected to the rest of the brain through cycling membranes.These are the actions, but what are the links between impulses and ideas, or words?

There must be a molecular equivalent to computer memory, some persistent physical state that endures, so it can be used as a reference at another time. Whether it’s an odor, a face or a connection, our minds must have memories.

The clue is these complex proteins. The way they are organized affects how easily they transmit an impulse. Their shape and the way they interact with other proteins is a physical state that provides an enduring record, a connection between times. Organization is the key. We don’t have the tools to measure such subtle changes in state, but we now have a path towards understanding.