The neurotransmitter acetylcholine, a brain chemical already established as being crucial for learning and memory, appears to be the key to adding details to a memory. In a study with rats, Norman Weinberger, research professor of neurobiology and behavior, and colleagues determined that a higher level of acetylcholine during a learning task correlated with more details of the experience being remembered. The results are the first to tie levels of acetylcholine to memory specificity and could have implications in the study and treatment of memory-related disorders.
The findings appear in the November issue of the journal Neurobiology of Learning and Memory.
"This is the first time that direct stimulation of a brain region has controlled the amount of detail in a memory," said Weinberger, a fellow at UCI's Center for the Neurobiology of Learning and Memory. "While it is likely that the brain uses a number of mechanisms to store specific details, our work shows that the level of acetylcholine appears to be a key part of that process."
In their experiments, the researchers exposed rats to tones of various frequencies. During some of the trials, they paired one tone with stimulation of a section of the rats' brains known as the nucleus basalis, which relays commands to the auditory cortex by secreting acetylcholine. During some experiments, the stimulation of the nucleus basalis was weak, whereas in other animals the stimulation was stronger. When the tones were replayed the next day, the scientists could measure how well they remembered the various frequencies by measuring changes in their respiration rates.
The results showed that a weak activation of the nucleus basalis, which resulted in a small amount of acetylcholine being released, did lead the rats to remember the tones but not specific frequencies. However, when the stimulation was greater (leading to the higher level of acetylcholine release), the rats also remembered the specific frequencies.
"We have always known that acetylcholine plays a major role in learning and memory," Weinberger said. "For example, the major treatments currently available for Alzheimer's disease work by making more acetylcholine available in the brain. Finding ways to control the levels of this key transmitter would be crucial for treating a number of memory-related disorders."
Weinberger is a pioneer in research in the field of learning and memory in the auditory system. In a study published in 2005, he discovered a neural coding mechanism that the brain relies upon to register the intensity of memories based on the importance of the experience. The study presented the first evidence that a "memory code" of any kind may exist. His laboratory also was the first to induce a specific memory by stimulating the system involving acetylcholine in the brain, setting the stage for the latest findings.
Farnaz Khadem | EurekAlert!
Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
22.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology