For the first time, scientists have directly measured and confirmed widespread deficits of muscarinic acetylcholine M1 receptors in the living brains of people with schizophrenia. Using a novel PET radiotracer, researchers found a 13% to 19% reduction in M1 receptor availability across multiple cognitive regions, linking these deficits to memory and learning challenges rather than positive symptoms.
The Research
Led by Dr. Deepak C. D'Souza at Yale University School of Medicine and VA Connecticut Healthcare System, the study published in Biological Psychiatry (July 2026) used the radiotracer 11C-LSN3172176 to scan 20 schizophrenia patients and 20 healthy controls. The results showed significant M1 receptor loss in cortical and subcortical areas—including the hippocampus, prefrontal cortex, and striatum—that are critical for cognition, learning, memory, and executive function. Importantly, the degree of M1 deficit correlated more strongly with objective cognitive impairment than with psychotic symptom severity. This work overcomes a major limitation of prior postmortem studies, which could not rule out effects of medication or illness duration.
Why It Matters
This finding validates a major shift toward non-dopaminergic treatments for schizophrenia. The drug xanomeline–trospium (COBENFY™) , recently approved as the first antipsychotic in over 70 years to work via muscarinic receptors, now has direct biological support. For your own brain, understanding M1 receptors highlights how acetylcholine fuels memory and focus. While schizophrenia involves extreme deficits, even mild M1 dysfunction in healthy individuals can affect learning and attention, which is why choline-rich foods and cognitive training may boost mental sharpness.
What You Can Do
Support your brain's acetylcholine system naturally: eat eggs, fatty fish, and broccoli (rich in choline), engage in memory exercises, and stay mentally active. Avoid anticholinergic medications (e.g., some antihistamines) when possible, as they can impair cognition. And take a free IQ test to benchmark your own cognitive abilities—tracking changes over time helps you see what works.
Source: Neuroscience News
Curious about your own brain? Take our free adaptive IQ test or try 306 brain training levels.
