When I was a child, I remember hearing something that turned my understanding of what it means to be human upside down. We were talking about depression, and this person said something to the effect of “well with some people it’s not just sadness or something psychological; some people just have a chemical imbalance that makes them feel depressed.” Chemical imbalance? I still remember that conversation because it struck me as strange and confusing that chemicals could influence the way you think or feel.
Now, after studying neuroscience for the past 10 years, I look back and realize that, just like Alice in Wonderland, that rabbit hole goes deeper than I could have imagined. When I was young I found it baffling that chemicals could influence how I think or how I feel; now, I know that chemicals are how I think and they are how I feel. Chemicals don’t influence your thoughts, they are your thoughts.
This can be a very uncomfortable fact for many people. There is no thought or emotion deeper than the brain. And the brain is made of roughly one hundred billion neurons squirting chemicals at each other. The part of you reading and understanding these words, the part of you that calls itself “I”, and the part of you that falls in love is a brain. That fact is what made me fall in love with neuroscience; I can’t think of any topic more interesting than how a biological system creates the rich experience of having a human mind.
In that context, understanding how these neurons work and what those chemicals are doing is not just another mundane examination of cellular function, it is the study of how you think and feel the way you do. It is the study of what you are.
For the next few posts I want to write about just what these mysterious chemicals are and what they are doing. These tiny little molecules are responsible for making you think, feel and behave the way you do. They are the reason when you walk into the grocery store and see on display a hot plate of donuts you suddenly find one in your shopping cart even though “donuts” are nowhere to be found on your shopping list. They are the reason why drinking coffee makes you feel alert. They are the reason why rubbing your sore back actually makes the pain go away (briefly). If you find this connection between tiny chemicals floating around in your brain and the deep complex experience of being a human being fascinating then join me as we walk through different neurotransmitter systems to see what neuroscience has taught us about what they do and how they work.