Researchers increasingly think there may be two main subtypes of Parkinson's—a 'brain first' version that starts in the olfactory bulb, and a 'body first' version that originates in the gut.

People with Parkinson's or a family history of the disease appear to have distinctive changes in their gut microbiome that may be linked to disease progression.

Small trials transplanting dopamine neurons into people with Parkinson's disease showed early promise in 2026, and the approach was available to patients in Japan under government oversight.

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

Dysfunctional mitochondria may be a cause of Parkinson's, according to a growing body of research in rodents.

Some dementia cases may be linked to treatable microorganism infections in the brain.

Chronic exposure to loud traffic noise is associated with a higher risk of developing Parkinson's disease.

Among Parkinson's patients, 8 or more hours of consistent weekly physical activity has been linked to a slower rate of mental and physical decline.

GLP-1 drugs are under investigation for treating Alzheimer's, Parkinson's, and drug addiction.

Schizophrenia is being studied with pea-sized 'mini-brains'

A super-sniffer smelled her husband's Parkinson's disease years ahead of symptoms.

Researchers are exploring neural links between Alzheimer's and autism

Alzheimer's brain changes may begin years before symptoms appear.

Vitamin B1 is linked to gut motility—helping fight constipation—in 2026 research

Gut bacteria are evolving and can acquire as many as 100 new genes per year, on average.

Scientists have traced how mice connect the dots between foods that sicken them and knowing to avoid the substance—even when the dodgy food wasn't the most recent meal they ate.

Face and neck massages improve cerebrospinal fluid flow in mice, raising questions about potential applications for clearing abnormal protein buildup in patients with Alzheimer's and Parkinson's.

A planned clinical trial to treat a rare lysosomal storage disorder in utero has buoyed hopes of providing prenatal gene therapies, but it was still awaiting FDA approval to begin enrolling patients as of May 2026.

How fecal transplants work

Gut microbiome rewrites may help reduce allergies

Paul Broca, a French brain researcher in the 19th century, hypothesized that humans evolved to trade in our "bestial sense" of smell for higher brain capacity.

The benefits of deep brain stimulation for treating substance use disorders remain uncertain amid inconsistent results for this surgical implant intervention.

Researchers are investigating how altering the gut microbiome may influence the development of rheumatoid arthritis, which is an autoimmune disease.

How frontotemporal dementia changes your personality

Specific gut microbiome 'fingerprints' are associated with cancer recurrence, with up to 94% accuracy.

The composition of our gut microbiome may influence addiction by triggering brain inflammation in regions of impulse control and increasing the severity of withdrawal symptoms.

Explore this 1440 Original video offering a primer on Alzheimer's disease and what's known about its incidence, causes, and more.

Early-onset Alzheimer's can appear as early as age 30, but estimates of its prevalence remain uncertain.

Some people who stutter have higher levels of dopamine in their brains than people who don't, and researchers say medications that boost dopamine—such as ADHD stimulants—may worsen stuttering.

Genetic blood test offers an estimated clock on when Alzheimer's symptoms may appear

Recent evidence raises the question of whether conventional wisdom about amyloid plaques and their connection to Alzheimer's is wrong.

The reason some people love exercise may be because of their microbiome

JJ Schildkraut theorized depression is linked to brain chemical imbalances—in 1965

In 2026, University of Cambridge researchers reported that a group of gut bacteria called CAG-170 may be a key marker of good health, occurring far more often in healthy individuals and less commonly in people with chronic diseases.

Could all mental health disorders have a unifying 'p-factor'?

People with a sleep disorder called REM Sleep without Atonia don't experience the temporary paralysis of skeletal muscles that typically occurs during REM sleep—instead, they have vivid dreams that they act out during sleep.

"Plaques" and "tangles" are top potential causes of Alzheimer's—but questions remain

See how the gut and the brain communicate through a bundle of nerves running from the brain to the digestive tract, serving as both a physical and chemical link.

Read the original 1907 paper on the first known Alzheimer's patient, which was identified by Dr. Alois Alzheimer.

Like fingerprints, brain anatomy is unique too

Minorities are largely underrepresented in medical research, which compromises our understanding of how conditions and treatments may affect various populations, but recent efforts, like the African Ancestry Neuroscience Research Initiative and new genome research studies, are seeking to close that gap.

Gene expression patterns are similar between ASD, schizophrenia, and bipolar disorder

See how Parkinson's death rates vary widely by state, even as the disease's death rates for older Americans have climbed by about a quarter in just a decade.

Scientists are reevaluating the causes of Alzheimer's beyond the amyloid hypothesis after numerous experimental drugs designed to target that theory have failed.

Roughly 15 of every 1,000 people in the US have smell disorders, and these issues with smell grow more common as people age.

Retired professional soccer players are showing signs of potential neurological impacts in midlife, according to a study presented at the July 2026 Alzheimer's Association International Conference in London.

Pig-to-human transplant work has raised concerns about donor pigs' living conditions.

Visualize the difference between a healthy brain and one with Alzheimer's.

Deep brain stimulation helps manage movement in patients with neurological disorders

People with schizophrenia have triple the risk of developing diabetes

GLP-1s may lower inflammation, possibly helping to combat cognitive decline