Loss of motivation may be linked to Alzheimer’s disease

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In a study from Indiana University, scientists found why neuropsychiatric symptoms, such as apathy and irritability, appear in most Alzheimer’s disease patients before the onset of memory loss.

The team found a receptor in the brain that leads to a loss of neurons and synaptic structure when used in an Alzheimer’s disease model.

The study focused on a critical brain region processing motivation. Located in the ventral striatum, this region is not studied much among Alzheimer’s disease researchers.

It’s mainly researched to understand motivational and emotional processes.

Previous studies have shown that the volume of this region, like the cortical and hippocampal regions in the brain, is reduced in adults with Alzheimer’s disease.

Some of the neuropsychiatric symptoms among people who suffer from substance abuse—apathy, mood swings, anxiety—are also found in Alzheimer’s disease patients.

These neuropsychiatric symptoms tend to occur earlier than memory loss, but no effective treatments are available.

In the study, the team identified synaptic calcium permeable receptors (CP-AMPARs) in the nucleus accumbens in an Alzheimer’s disease model.

The receptor, which is normally absent in that part of the brain, gives permission for calcium to enter the neurons.

This leads to an overload of calcium, which leads to a breakdown of its synaptic structure.

In turn, calcium accumulation triggers a cascade of intracellular changes that can be lethal to the neuron by amplifying calcium overload via a positive feedback mechanism.

This synaptic loss in the brain causes motivation deficits.

Knowing this, the team says that targeting these receptors in the brain and blocking them could prevent or delay the onset of Alzheimer’s disease-associated neuropsychiatric symptoms, and ultimately cognitive deficits.

If you care about Alzheimer’s disease, please read studies about the likely cause of Alzheimer’s disease, and new non-drug treatments may help prevent Alzheimer’s.

For more information about brain health, please see recent studies about antioxidants that could help reduce dementia risk, and Coconut oil could help improve cognitive function in Alzheimer’s disease.

The study was conducted by Yao-Ying Ma et al and published in Molecular Psychiatry.

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