Function of Nicotine Receptors in the Brain Key to Maintaining Cognitive Capability in Aging

Yale School of Medicine
Wednesday, 1 November 2000

Provides Clue to Devastation of Alzheimer's Disease

A new study by Yale researchers shows that loss of nicotine receptors in the brain in the late stages of Alzheimer's Disease may contribute to the cognitive impairments associated with the disease.

Researchers have long known that loss of nicotine receptors in the brain was a clear manifestation of Alzheimer's Disease. This new study in the journal Neuropharmacology shows that loss of nicotine receptors in the brain results in poor performance in learning tasks following aging.

Marina Picciotto, assistant professor of psychiatry and pharmacology at Yale School of Medicine, said that when they lost all of the nicotine receptors in the brain, the animals used in the study also became unable to develop an addiction to nicotine.

"We showed that these receptors are absolutely critical for getting addicted to nicotine, and now we know they also are critical for maintaining cognitive functioning in aging," Picciotto said.

Nicotine binding sites are those areas in the brain that normally are activated by neurotransmitted acetylcholine. "Nicotine binding sites are lost selectively in patients with Alzheimer's Disease," Picciotto said.

She said the research also shows that the animal models they are using offer important insights into neurological changes in humans. For instance, the animals in the study exhibited normal learning and memory until they aged, and then there was accelerated impairment in learning and memory.

It is unlikely that the loss of nicotine receptors alone are responsible for diminished cognitive capability, she said. "We think the nicotine receptors become more important as people age because of neurons lost in other areas of the brain, such as the cortex and hippocampus," Picciotto said.

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