Study Uncovers Brain Pathways Connected to Alzheimer’s Memory Loss and Mood Changes

Alzheimer’s disease not only robs people of their memory but also affects mood, often causing anxiety and depression. Until now, scientists haven’t fully understood how these symptoms are connected in the brain.  

The study, published in Neuron and led by UNC School of Medicine’s Juan Song, PhD, focused on two distinct groups of brain cells in a region called the supramammillary nucleus (SuM) located in the posterior hypothalamus – a small region deep in the brain. One group helps regulate memory, while the other influences emotional responses. While examining Alzheimer’s model mice, researchers discovered these two circuits do not function properly, but when the team used light-based stimulation to activate each pathway, they were able to restore memory or emotional function separately. 

“We were surprised that by selectively activating each pathway, we were able to restore either memory or mood in Alzheimer’s-model mice,” said Song, senior author. “This level of precision in how a single brain region contributes to two very different symptoms—cognitive decline and anxiety or depression—was unexpected and highlights an exciting new avenue for targeted therapies,” she said. 

Most therapies focus mainly on slowing memory decline, but patients also struggle with anxiety and depression, which greatly affects their quality of life.

“This could mean moving toward more personalized, circuit-based therapies that not only preserve memory but also improve emotional well-being, helping patients and families manage the full spectrum of challenges that come with Alzheimer’s,” said Song.

(Newswise/HG)