Organic chemistry students complaining they cannot cram any more information into their beleaguered brains may have to think up a different excuse.
A recent study-conducted by researchers at Duke University Medical Center in conjunction with scientists at the University of North Carolina at Chapel Hill-has further demonstrated the efficiency of the brain in maintaining old information while remaining malleable and able to store new knowledge.
Dr. Michael Ehlers, an associate professor of neurobiology at DUMC and a Howard Hughes Medical Institute investigator, led the research team that explored new questions, contributing to a growing understanding of how the brain learns and stores memories.
Ehler said that previous investigations in neurobiology established a connection between the efficacy of memory and the number of receptors found among neurons in the brain.
The receptors catch the neurotransmitters sent from neuron to neuron across the synapse. These vital receptors, however, can sometimes escape from their designated synapses. Ehler and his colleagues examined what precisely happens to these rogue receptors.
The team discovered specific molecules in the brain capture loose receptors and transfer them to a "recycling center" on the dendritic spines of the neurons. There, they are restored to working order and then returned to the synapse where they resume their role in the neurotransmission process.
"Certain connections between cells are activated by certain memories," Ehler said. "Depending on the number of receptors between cells, a memory can be easier to recall and activate."
He added that a malfunction in this system may be associated with certain neurological disorders ranging from autism to dementia.
"We find that the recycling of receptors is abnormal in Alzheimer's patients in the very early stages," Ehler said. "Before any gross pathological change, we see these subtle defects."
In addition to possible medical benefits, Ehler said his focus on memory is a subject of importance to the general public.
"Everyone has had the experience of not being able to remember a name," he said.
Ehler added that the complicated network of neurons and receptors regulates daily life.
"All common, everyday experiences arise from these much more basic microscopic cellular events," he said. "This is what makes neurobiology so fascinating."
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