Neurotransmitters Systems One pill makes you larger Commentary

Henry Hallett Dale, George Barger, Otto Loewi neuroscience

Neurotransmitters

• Knowing that the ergot fungi
• slows uterine contractions in premature labor,
• and interested in physiologically active chemicals,
• Dale and Barger isolated acetylcholine from ergot
• and demonstrated that it causes effects similar
• to the stimuli from the parasympathetic nerves
• that control blood pressure and sweating.
• This work established acetylcholine
• as a possible neurotransmitter. Debate had been raging
• whether nerves communicated electrically
• or chemically.
• Loewi did the experiment that proved
• that a chemical, later shown to be acetylcholine,
• transmitted from the vagus nerve of one frog’s heart,
• where it slowed the heart’s beating,
• could be transferred to the heart of another frog
• to slow the second heart’s beating.
• Over one hundred chemical neurotransmitters
• have been identified, although scientists have not
• identified all neurotransmitters
• nor determined their purposes.

Systems

• Your noradrenaline system regulates arousal and reward,
• keeps you attentive, helps you feel the effects are worth the effort.
• What shall we say about your dopamine system?
• It governs your motor system and your motivation.
• Too little and you might have Parkinson’s disease;
• too much and you might be schizophrenic.
• Cocaine keeps dopamine in your receiving neurons longer.
• What does your serotonin system not relate to?
• It regulates your ability to feel pain.
• It regulates your appetite, your sleep, your mood,
• your temperature, your cardiovascular system,
• and the secretions of your glands.
• Prozac enhances the effects of natural serotonin.
• Finally, your cholinergic system
• regulates your memory and your ability to learn.
• Do you remember what you just read?
• If so, no doubt the neurotransmitter acetylcholine
• has been doing something in your head.

One pill makes you larger

• Some neurotransmitters are excitatory
• and some are inhibitory.
• All neurotransmitters are targets for the drug industry.
• Chemicals alter your body; chemicals alter your mind.
• I write this not to establish a principle
• that all chemicals are the same, but to warn
• that any drug you take will be mixed
• into the broth of a finely seasoned stew
• in which simmer exotic vegetables and meats
• from plants and animals that science has not named.
• Sorry. That’s a bad metaphor.
• You are a vast work of fine art
• which, if damaged, only the most careful conservator
• would dare try to restore.
• You are a finely woven magic carpet
• of rare fibers, many colored, intricate of design.
• No other carpet is exactly like you.
• Your irregular pattern is impossible to trace,
• but something in its indescribable pattern makes it fly.
• You are a long and complex tale, a fable
• that exists in only the story-teller’s mind,
• so that to interrupt him would be to risk his forgetting
• how all the loose ends are supposed to resolve.
• You are actually a foreign land that has been only poorly mapped,
• whose people have strange customs and speak a strange language,
• but that has been invaded by gnats, snakes, moles,
• transister radios, poisonous vehicles, and gas warfare
• from the modern world. You are their representative;
• you must explain to them concepts that make no sense,
• and you must explain things from this odd land
• that we invariably do not understand.
• Some claim that any refined substance, like sugar,
• is a drug that can be both damaging and addictive.
• Yet you must eat, and you may choose
• to take aspirin for an ache, drink a glass of wine,
• or stress your body to experience a rush of adrenalin
• or an endomorphine high. These are not the same
• as experimenting with mind-altering mushrooms,
• but who’s to say? Who’s to judge? Whose
• body are we talking about but your inner temple!
• Your body is a chemistry laboratory, in which
• many oddly shaped test tubes and vials overflow
• with weirdly colored, pungent liquids that no one has labeled.
• Some vials have broken; smoke rises to the ceiling.
• Strange equipment, burners, filters, and mixers abound,
• but the laboratory manual has not been written,
• and you are here to conduct an experiment
• whose purpose has not been agreed to.
• Common table salt is essential for life,
• but eating too much can cause you great distress.
• Eating too much of anything would be too much.
• Even drinking too much water can kill you.
• You can buy a book that tells you
• what not to put up your nose,
• how much salt or water you should ingest,
• and why you should put it up your nose.
• I will not pretend to compete
• with the medicine men and global corporations,
• but I know that sometimes a shock
• can interrupt your negative patterns
• and awaken your creativity, and that,
• to add one last metaphor to this allegory,
• most clocks need to be reset once in a while.