Brain & body: the dopamine path

Welcome back to the Weekly Brain Buzz. Last week we talked about stress eating and the hypothalamus. Check it out here if you missed it and want to learn about how to tame the hippopotamus inside your head.

This week is all about your brain on…


Normally, we think habits = bad. There’s a negative connotation to the word habit, however habits are evolutionarily designed to make your life easier.

Habits put you on autopilot, they make tying your shoes and driving to work a no brainer. A no brainer, besides one particular part of the brain, the Basal Ganglia.


Here’s how it works:

The dopamine neurons in the basal ganglia become highly active during a regular routine that leads to a favorable outcome, like having fresh, sparkly teeth or protective shoes on your feet, or a full, happy belly.

This happens with the help of NMDA receptors, receptors that are sensitive to a neurotransmitter called glutamate. Glutamate approaches, NMDA receives it, and the dopamine cell is excited.

Dopamine is the neurotransmitter that is all about reward and pleasure. It keeps you motivated. When dopamine releases in the brain, it feels good.


So, every time you go to do that habit, the brain says, good job! Task completed!

That’s how habits become habits, the circuitry of the brain keeps you coming back for more.

So, how do you break a bad habit or start a new one? 

First, I’ve got to tell you an interesting fact. 

Have you ever heard of Parkinson’s Disease? It’s a disease where the substantia nigra in the basal ganglia begins to break down. The dopamine cells in the substantia nigra no longer work. And what happens to these patients? They lose their old habits and have a hard time forming new ones. So, good news for dropping bad habits, bad news for trying to start a new exercise routine.

But scientists, such as Dr. Joe Z. Tsien, have an interesting idea. If you can manipulate the dopamine output in the brain, maybe you can help break or make a habit.

Dr. Tsien and his crew tried this out in a study where they blocked the NMDA receptors in one group of mice and kept them unblocked in another group.


Ok, so this gets really cool.

The scientists somehow trained these mice to push a lever for food. That is really cool on its own 🙂 but it gets better. What they found was that the mice who had the NMDA receptor block and couldn’t receive the dopamine reward, never formed a habit of pushing the lever. They stopped pushing the lever when they were full!

The normal mice, because they received dopamine every time they pushed the lever, formed a habit and would go to the lever for more food despite having eaten enough.

Wow. This study paints such a beautiful picture of the reward circuit and how we do things on autopilot just for that little spike of dopamine.

That’s not all though.

There’s something else happening in the brain. Just as the Basal Ganglia and dopamine are firing up during a habit, the prefrontal cortex is shutting down. So, once a behavior becomes automatic, the decision making part of your brain goes asleep. It no longer needs to work for that particular task.


From the vantage point of efficiency, this makes sense. Let the basal ganglia put you on autopilot, turn off the prefrontal cortex, and now you have more mental capacity to do other things. This is how you can multi-task. The basal ganglia takes care of the driving as you sing along to the radio or talk to your mom on the phone.

The bad thing is, if the behavior that has become an automatic one is a bad behavior, it’s hard to stop. You don’t have your rational brain to help you make the healthier decision. Cue addictions and habits like overeating or smoking.

So, what do you do with this information? You’re probably thinking, “this cool to know, but, Hannah, I don’t have a device to change the dopamine output in my brain to stop that bad habit.” Too much science, not enough practicality.

Got it.

Cool news is: you CAN modulate the dopamine in your brain just like Dr. Tsien did with the mice without having to open your brain and probe your basal ganglia! There are things you can do to get yourself off of autopilot and back in control.

There are four key steps:


If you do this YOU are regulating the dopamine output in your brain because you’re rewarding yourself, you’re choosing the reward, you’re choosing the habit, you’re choosing what makes your brain release dopamine.

I want you to be able to do this in concrete steps, starting today, so I’m going to break it down even further.

The first step is to become aware of your habits, so…   

make a list of the things you do on autopilot. Sometimes the things on the list aren’t bad, like tying your shoe or washing the dishes. BUT, if you can get off of autopilot when you do those things and truly experience yourself doing the tasks, it becomes a lot more interesting and enjoyable.

So, what’s on your list? Good and bad.

  • Picking up your phone every 2 minutes to check for messages?
  • Eating food as your watch a show or youtube video?
  • Over-eating once you’ve started munching on those chips?
  • Reaching over for food or a drug when feeling stressed?
  • Going on a daily run to decompress?
  • Biking to work?
  • Making coffee in the morning?

After you’ve identified your habits, notice when the habit loop is about to start, notice the cue for the habit. After you notice the habit loop, this is where the magic happens. This is where you change your behavior.

Here’s exactly how to do it:

I’ll use the example of overeating.

  1. Identify the habit: I tend to overeat like a ravenous monster even when I’m full.
  2. Notice when you’re about to go into the habit: oh no, I’m full but I feel myself wanting to dive in even more.
  3. Take a deep breathe and instead of following you urge, replace the old habit with a new one: I’m not going to overeat, but I’m going to go brush my teeth or chew a piece of gum or brew a warm cup of tea.
  4. REWARD THYSELF: I didn’t overeat, yay! Now I’m going to go watch a TED talk and fill my head with inspiring ideas 🙂 DOPAMINE!

Do this enough times and you’ve gotten rid of an old habit and created a new one that is much more healthy. And you did it in a way that changed your brain for the better! Go you! Putting Dr. Tsien’s research into action. You can send him a thank you letter.

You can also use these steps to change up your routine. Wanna stop running so much and begin swimming because your doc said your knees are gonna give out? Use these same four steps to stop your old running habit and pick something less harsh on your joints.

So, that’s your brain on habits 🙂

Wanna break a habit or form a new one? START TODAY! There’s no better time than now. If you have questions or want suggestions on breaking your particular habit, feel free to reach out to me. Let’s talk!

From my heart and brain to yours,



Hannah Heimer
Hannah Heimer

I’m a brain enthusiast and yoga fanatic. I work as a researcher at the University of California, San Diego while also running a yoga business on the side.

I use brain research and yoga as a springboard to blog about lifestyle, health, happiness, and how it all relates to your brain.

Just like the nerve cells in our brains, I love making new connections. So, feel free to reach out. For more info on yoga and the brain, take some time to explore