Dopamine
Episodes
In this clip, Dr. Andrew Huberman discusses the power of effort, dopamine in motivation, and the mindset needed for effective learning and growth.
In this clip, Dr. Andrew Huberman discusses dopamine's role in motivation and strategies for maintaining stable levels.
In this clip, Dr. Andrew Huberman discusses using negative visualization, discomfort, and cold exposure to overcome procrastination and boost motivation.
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In this clip, Dr. Andrew Huberman discusses the power of effort, dopamine in motivation, and the mindset needed for effective learning and growth.
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In this clip, Dr. Andrew Huberman discusses dopamine's role in motivation and strategies for maintaining stable levels.
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In this clip, Dr. Andrew Huberman discusses using negative visualization, discomfort, and cold exposure to overcome procrastination and boost motivation.
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In this clip, Dr. Andrew Huberman discusses social media's dopamine effects, usage limits, and its impact on relationships and ADHD.
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In this clip, Dr. Andrew Huberman discusses how caffeine and other stimulants impact the release of dopamine in the brain.
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Dr. Andrew Huberman discusses the role of dopamine in driving motivation and offers practical tools for enhancing mood and focus.
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In this clip, Dr. Giselle Petzinger discusses how no evidence exists that lifestyle factors, such as diet and exercise, can cure Parkinson's disease or obviate the need for dopamine replacement.
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In this clip, Dr. Giselle Petzinger discusses how intense exercise can impact motor scores in people with Parkinson's disease.
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In this clip, Dr. Giselle Petzinger explains that strenuous exercise affects dopamine sensitivity in the brains of people with Parkinson's disease.
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In this clip, Dr. Giselle Petzinger highlights some of the risk factors for Parkinson's disease, and discusses how this is likely a multifaceted problem.
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In this clip, Dr. Giselle Petzinger explains how the loss of dopamine disrupts circuitry in the brains of people with Parkinson's disease.
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Dr. Giselle Petzinger discusses new findings in Parkinson's disease research, emphasizing exercise's role in delaying disease progression.
Topic Pages
News & Publications
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Insulin improves dopamine signaling in regions of the brain associated with eating behavior. www.sciencedaily.com
Insulin signaling in the brain influences behavior, weight regulation, motivation, and cognition. Previous research demonstrates that insulin resistance reduces brain volume and cognitive function in middle-aged adults. Results of a new study demonstrate that insulin interacts with dopamine to modulate reward-based behavior and whole-body metabolism.
Dopamine is a neurotransmitter that regulates activity of the mesocorticolimbic system, a region of the brain involved in reward-based learning. Mesocorticolimbic circuits transmit information from the midbrain to the ventral and dorsal striatum, prefrontal cortex, amygdala, and hippocampus to coordinate emotions, memories, and impulses involved in eating and other rewarding behaviors. Previous research has demonstrated that insulin interacts with dopamine, altering activity of the mesocorticolimbic systems, inducing feelings of satiety and decreasing high-calorie food seeking. However, much of the existing research has been conducted in mice, using very high levels of insulin, making translation to humans difficult.
The investigators assigned ten male participants (average age, 27 years) with a normal BMI (average BMI, 24) to receive either intranasal insulin or a placebo and undergo a combined PET and MRI scan after having fasted overnight. The researchers gave participants an injection of a radioactive marker called [11C]-raclopride that binds to dopamine receptors so they could measure dopamine-related brain activity during the scan. Participants also completed surveys to assess eating behavior and provided a blood sample for measurement of insulin and other hormones.
Following administration of intranasal insulin, [11C]-raclopride synaptic binding potential increased in the ventral and dorsal striatum, suggesting an increase in the number of dopamine receptors in these regions. Accordingly, synaptic dopamine concentrations (dopamine that has not bound to a receptor and internalized by the neuron) decreased. Ultimately, this increase in dopamine signaling reduced resting-state activity in the ventral and dorsal striatum and improved functioning of mesocorticolimbic circuits 15 to 45 minutes after insulin exposure. As the participants' response to insulin exposure increased, so did their scores on tests of subjective wellbeing and cognitive control.
This study, which demonstrated the effects of intranasal insulin on dopamine activity in the mesocorticolimbic system, has important implications for reward-based learning, eating behavior, and obesity. Future research should include participants with insulin resistance to gain a better understanding of the effects of obesity and metabolic disease on the brain.
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Stimulant medications increase willingness to expend effort, not ability. www.sciencedaily.com
Executive function refers to a set of cognitive abilities that facilitate control over voluntary behaviors, including attention control, working memory, and cognitive flexibility. While executive functions are critical for complex tasks such as planning, they are also mentally taxing. Without sufficient motivation, people with poor executive function may struggle to meet goals. Researchers report their findings that dopamine signaling is responsible for the effects of Ritalin and other stimulant medications on motivation and executive function.
Dopamine is one of the most abundant neurotransmitters in the brain and is involved in reward-motivated behavior, learning, and memory. Activities that provide a reward (e.g., food, money) increase dopamine levels, causing a sensation of pleasure that enhances learning by deeply encoding memories related to rewarding activities. Motivation to complete a task is based, in part, on whether a task is judged to provide sufficient pleasure relative to the cost of its required effort. Capacity to synthesize dopamine varies from person to person; however, lower dopamine levels in key brain areas are associated with attention deficit hyperactivity disorder (ADHD), substance use disorders, and Parkinson’s disease. Drugs such as methylphenidate (i.e., Ritalin), a medication used to treat ADHD, and sulpiride, a medication used to treat schizophrenia and depression, interact with dopamine receptors in the brain and can increase motivation.
The authors recruited 50 healthy adults (ages, 18 to 43 years). Participants completed a test called a cognitive effort-discounting paradigm. In this test, participants are asked how much money they would want to receive in exchange for completing tasks of varying difficulty. The authors measured the estimated effort cost as the amount of money necessary to make participants willing to perform a cognitively difficult working memory task. Participants completed effort-discounting tasks under the influence of 20 milligrams of methylphenidate, 400 milligrams of sulpiride, or a placebo on three separate testing days. The researchers used a positron emission tomography (PET) scan to measure dopamine synthesis capacity in the caudate nucleus, a brain region responsible for reward-based learning. Finally, the researchers used a statistical model based on the effort-discounting task to further explore the effects of methylphenidate and sulpiride on motivation.
While on the placebo treatment, participants’ willingness to expend cognitive effort increased as their baseline dopamine synthesis capacity increased. Notably, while performance on the working memory task decreased with difficulty, there was no relationship between task performance and dopamine levels. Both methylphenidate and sulpiride increased willingness to expend cognitive effort, but only in participants with low baseline dopamine synthesis capacity. Using their computer model, the investigators found that methylphenidate increased feelings of reward while sulpiride decreased effort cost. Further, they found that the cost-benefit analysis involved in the decision to expend effort occurs early in the decision-making process and can be measured by patterns in gaze (focusing on a reward or cost of a task) during cognitive testing. While higher baseline dopamine synthesis capacity and drug administration did not affect gaze patterns directy, higher dopamine levels strengthened the impact of gaze and attention to the benefits versus the costs of a decision.
These findings indicate that Ritalin and other attention-enhancing drugs work by increasing willingness to attempt cognitively-difficult tasks, not the ability.