Philosophy or Chemistry?

Brainchemistry

Back in Grad School, I once volunteered to entertain elementary school kids with some fun chemistry* and in the process distributed stickers that said "This is a product of chemistry", telling the kids that they can stick them on pretty much anything they want, and it would be true.

Traditionally we have always divided our understanding or perception of the world into "science" and "philosophy", one dealing with tangible materials and proven theories and the other dealing with all the gray areas that have no tangible "proof". For example, biology dealt with cells and chemicals therein, while philosophy dealt with thoughts and consciousness. But with the advent of "neuroscience" the divide is a lot less fuzzy, and direct connections have been established between chemicals and thoughts, so much so that we now wonder if thoughts are merely spin-offs of synaptic chemical reactions. Conversely, we may also wonder if thoughts produce these chemical reactions, and thereby create the world as we see it a la The Matrix or the Vedantic Maya.

Advances in microbiology and biochemistry^†of the human brain and the central nervous system have identified a whole army of chemicals and chemical reactions that sustain human life in all its physical and mental glory. And the discovery of these chemicals have in turn burgeoned a pharmaceutical industry that now focuses on these chemicals and their analogues for the treatment of a variety of diseases caused by their irregularities and imbalances. For example, molecular mimics of neurotransmitters such as L-Dopa are now routinely used to compensate for the loss of dopamine that leads to Parkinson disease, the side effect being overactive synaptic reactions, leading to hallucinations, as I have, in the past, sadly witnessed in a favorite uncle. The destruction of the neurotransmitter acetylcholine results in Alzheimer's disease, and cholinesterase inhibitors fight the assault of acetylcholinesterase, thereby reducing or delaying the severity of the memory loss. Prozac, the most widely (ab)used anti-depressant works by preventing scavenging of serotonin thereby increasing the amounts of these endogenous opioids that boost mood. The common sleep inducer - Valium outwits the neurotransmittor GABA (which, when linked to its receptor site increases alertness) by competitively binding with the receptor sites.

The blood brain barrier acts as the guard on duty, preventing the entry of exogenous chemicals into the sensitive brain and thus makes the introduction of the neuro-medication into the nervous system a daunting task. As lipids can cross the barrier, these drugs are encapsulated in lipids in order to insert them into the closed system.

God_Brain

A high concentration of the neurochemicals in the blood can also cause the blood-brain barrier to be traversed, as is what happens with recreational (abusive) drugs ranging from nicotine to LSD. These neurotoxins react at specific synapses to alter thoughts and moods. Apart from recreational drugs, which we all know and agree to be a social evil, we knowingly or unknowingly consume neurochemicals that can adversely/conversely affect our thought processes. Japanese children are reportedly given tea laced with GABA to increase their mental alertness. Monosodium glutamate (MSG) commonly added to oriental cuisine can become a neurotoxin (The "Chinese Restaurant Syndrome" that I have personally had the (mis)fortune to experience) as glutamic acid is a neurochemical that is involved in cognition and memory. Most animal toxins including the venom of bees, scorpions, pufferfish, spiders and snakes contain neurotoxins that paralyse and kill.

The number of chemicals that are being found to contribute to the mental processes in humans is staggering. Such discoveries will ease the search for the elusive "self" or consciousness or perhaps complicate it further. Only time can tell.

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* As an aside, in that program, I taught kids to make silly putty using liquid glue and liquid starch. And when I asked the kids to "knead" the mixture well, one of the kids popped it into his mouth, having heard it as "eat" the mixture !

†Steven Rose, in The 21st Century Brain elegantly describes the difference between a microbiologist molecular biologist and a biochemist thus: Biochemists are concerned with 'dynamics, the metabolic interactions between the myriad protiens that stabilize the cell's metabolic web in, what the biochemist geneticist Henry Kacser once referred to as "molecular democracy"', while mol.biol. study the 'snapshots, all the proteins in the cellular bag at any one moment'.

Comments @ nOnoscience

1. Vijay Says:
   June 15th, 2007 at 7:34 pm

   Another wonderful post Lakshmi.
   Two hairs to split.

   When you really look, isn’t everything a product of physics? Not chemistry.

   In your second footnote you started out with a microbiologist who got transformed into a mol. biol.??
   Is that a typo or were you on some hallucinogenic alkaloid

2. Lakshmi Says:
   June 15th, 2007 at 9:51 pm

   Vijay, I still think it is chemistry, but am willing to give physics a chance ! And yes, GABA was not quite bonding with its receptors by the end of the post !

3. enjay Says:
   December 21st, 2007 at 3:41 am e

   Oh, wow! You have good stuff here..pretty much all biology today is being broken down to the physical/chemical level..and I love the point where the divide gets fuzzy.