When dopamine-producing brain cells die, it disrupts the basal ganglia, a brain region that acts as the traffic controller for movement.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder that affects the nerve cells (neurons) controlling muscle movement. As the motor neurons degenerate, they stop sending signals to the muscles, causing progressive muscle weakness and, eventually, death. This three-minute animation focuses on the mechanisms within the motor neurons that cause them to degenerate. By understanding these mechanisms, researchers hope to one day find a cure for ALS.

Neurotransmitters like dopamine, serotonin, and norepinephrine, along with increased brain-derived neurotrophic factor levels, enhance a wide range of brain functions. New research demonstrates a direct link between movement and numerous cognitive benefits, including memory, learning, and stress resilience.

Proteins in the brain perform various critical functions, such as helping neurotransmitters function or enabling electrical activity in the organ. These proteins must fold in specific ways to perform their duties, similar to paper airplanes. Sleep deprivation contributes to the gathering of misfolded proteins that aren't shaped correctly for their roles and so accumulate in undesired spaces, such as in the gaps between neurons.

Aging affects the brain perhaps more than any other organ in the body. Throughout life, the brain experiences radical shifts in the number of neurons, synaptic connections between neurons, and hormone levels that regulate our mood and processing.

Burnout isn't just a feeling—it physically affects the brain. Prolonged stress impairs regions of the brain responsible for decision-making, emotional control, memory, and more. It can also lead to chemical imbalances, like reduced dopamine and norepinephrine levels, that worsen these effects.

Although Alzheimer's disease is sometimes thought of synonymously with dementia, there are multiple types of dementia, which manifest in memory loss and other symptoms that make it challenging to perform daily tasks. These types include Lewy Body dementia, vascular dementia, and frontotemporal dementia. Parkinson's disease is not a form of dementia, but this movement disorder can sometimes develop into issues with memory and a formal diagnosis of dementia.

DBS is a surgical procedure that uses implanted electrodes to send electrical signals to targeted areas in the brain, interrupting abnormal neural activity. It may be implemented when medications lose effectiveness or cause disruptive side effects.

Dopamine is a neurotransmitter—a chemical released by neurons that enables neural communication—that makes people want things with an "almost animalistic desire," compelling them to snack or check phone notifications. Often misrepresented as a "pleasure" chemical, dopamine is involved in motivation, learning, attention, habit formation, and more. Trends like dopamine fasting overinflate its role in mental health and often use it as part of "straw man" biohacking claims.

The exact causes of Alzheimer's—and how to treat it—continue to be the subject of intense research. Two leading factors are amyloid beta plaques and tau protein tangles, which effectively pile up in the brain and interfere with neurons and cause cell death, which manifests as memory loss and other symptoms.

Depressed brains can have certain characteristic changes, including an overactive amygdala, reduced hippocampus size, and changes to the thalamus and neuromodulating chemicals in the brain.

Addictive substances or behaviors will typically flood our brains with more dopamine than usual. In response to the overstimulation, our brains will decrease the number of available dopamine receptors. This results in the need for more stimulus for the same response (tolerance) and a rise in negative feelings when the stimulus is absent (withdrawal).

Neurons transmit signals between one another at sites called synapses. Repeated interactions at these sites improve the efficiency of signal transmissions, making memories involving sensory data associated with those neurons easier to recall. Biochemical factors impacting these synaptic interactions affect memory quality.

Brain regions that control sleep sit adjacent to those that regulate the autonomic nervous system, which controls involuntary bodily functions like heart and breathing rates. These neighbors influence each other, meaning poor sleep can impair or negatively impact the ANS, further disturbing sleep.

Treatment for depression has historically hinged on the theory that the condition was caused by underactive or abnormal neurotransmitters, specifically serotonin and norepinephrine. This four-minute video by Yale Medicine details how these neurotransmitters didn't explain the symptoms of depression but, two other neurotransmitters involved in regulating mood and emotion did. GABA and glutamate, some of the brain's most plentiful neurotransmitters, may possibly be the source of depressive symptoms.

Skimping on sleep lengthens reaction times and blunts decision-making skills. At a certain point, the brain will try to sneak sleep where it can, shifting sections offline even as you remain awake. Going without sleep raises blood pressure, undermines the immune system, and increases one's risk of dementia.

Despite more than 100,000 people with Alzheimer's dying each year, the specific cause of death is not the disease itself. Often, secondary diseases arise from complications with the disease, including pneumonia, severe falls, malnutrition, or infection. Read more about the range of complications caused by Alzheimer's here.

High blood sugar levels in untreated diabetes roughen artery walls, increasing plaque buildup, heart disease, and high blood pressure risk. High levels also cause acid to build up in the bloodstream, potentially making the brain swell, the lungs fill with fluid, and the heart to beat arrhythmically—all fatal complications.

Certain gut microbes in mice trigger dopamine release and drive motivation to exercise more. Scientists are investigating whether humans carry similar microbial patterns that influence our natural inclination towards movement, exploring how unseen microbial ecosystems may shape mammalian fitness behavior and reinforce innate reward pathways.

Neuroscientist Judy Grisel breaks down the biology of addiction, examining how drugs hijack the brain’s natural reward system and create lasting neural changes. The physiological and neurological impacts of chronic drug use require a multifaceted treatment approach.

Cells are the building blocks of life, forming tissues and organs that keep our bodies working. As we age, cellular changes have progressive consequences on both the structure and function of our organs. This article examines this complex relationship as it relates to the incremental changes associated with aging.