BEIJING, May 22 (Xinhua) — In a new trial, scientists have targeted ultrasound pulses at macaques’ brains to control their decision-making judgments that could help treat human addiction and depression,media reported. By pointing ultrasound pulses at parts of the brain’s prefrontal cortex, it can influence the monkey’s judgment in computerized selection tasks, and if the treatment is applied to humans, painless ultrasound brain stimulation can treat behavioral decision-making disorders, including drug addiction and overeating, rather than medication or surgical treatment.
By pointing ultrasonic pulses at the frontal cortex of the brain, the macaques can be influenced to determine the judgment of the computerized selection tasks, allowing them to choose between one of the two tasks.
The therapy can also be used to treat mental illnesses such as depression and anxiety disorders in humans, as well as neurological disorders such as chronic pain and epilepsy, and brain diseases should be treated in a targeted and personalized manner, rather than providing cocktail therapy to patients. But to achieve this treatment, we need a tool that provides non-invasive, precise and personalized treatment to address the root causes of each patient’s condition, but so far there is still some distance to achieve this treatment.
Ultrasonic precision treatment refers to silent, high-frequency sound pulses aimed at the brain through an ultrasonic transducer, which is like an ultrasonic “scanning wand”. The sonic pulse targets the neural circuits of the brain, activating neurons and influencing neuronal control behavior.
By stimulating the macaque’s prefrontal eye field (FEF), the brain region that controls eye movement, researchers found that ultrasound can influence what the macaques see. The figure shows where the human brain’s “frontal eye field” is located.
Ultrasound is a high-frequency sound wave that has been used to stimulate neurons or nerve cells in the brain, and previous studies have shown that low-intensity ultrasound scans of rodents outside the head can stimulate neurons and cause muscle movement in other parts of the body.
To get more information, the researchers involved two macaques in an experiment that was widely used to study selective behavior, in which the macaques watched a virtual target in the center of a computer screen and then displayed the targets one by one from left to right.
In this experiment, the macaques naturally chose the target that appeared first on a computer screen, but by stimulating the macaque’s “frontal eye field” (FEF), the brain region that controls eye movement, the researchers found that ultrasound could affect the targets that the macaques see. In primates, the frontal eye field is located in the prefrontal cortex, the largest of the brain’s four main brain lobes, which play an important role in visual attention and eye movement.
Just as each hemisphere of the brain controls the muscles and glands on one side of the body, the researchers found that when ultrasound sedated the front alt-eye field in the left hemisphere of the brain, the monkeys were likely to choose the target on the right side of the computer screen in the experiment, as did the prefrontal eye field that stimulated the right hemisphere of the brain.
When ultrasound acts on the motor cortex of the brain, no effects are observed, and the motor cortex is associated with autonomous movement, but not to perception decision-making. To further test the effects of ultrasound on the brain, scientists gave different awards to macaques in the experiment.
The researchers found that when ultrasound sedated the front altimeter of the brain’s left hemisphere, the monkeys were likely to choose a target on the right side of the computer screen in the experiment, as might the target on the left side of the computer screen when stimulating the front eye field in the right hemisphere of the brain.
“Monkey A” selects any one of the goals to reward juice, and “Monkey B” rewards juice only when the first target is selected. Even if Monkey B chooses the first goal and is rewarded, ultrasound can still control its choice of the second target as the final decision. The team says their “neural intervention” can be used to determine which brain regions are associated with specific symptoms or behavioral conditions of the disease.
The study suggests that ultrasound can have a strong disruptive effect on the brain and can even interfere with people’s behavior, and behavioral interventions are our most important concern, such as the ability of scientists to correct people’s wrong decisions through ultrasound, or even to treat shaking their hands.
The researchers, who have created a prototype device that can be treated on the human body, plan to begin the first clinical trial of patients with severe depression within the next three years, and the study also provides valuable lessons for future applications of “ultrasonic neuromodulation” in animals and humans.
How do neurons work?
Neurons, also known as nerve cells, are “electrically excited cells” that receive, process and transmit information through electrical and chemical signals, and are one of the basic elements of the nervous system.
In order for humans to respond to environmental conditions, brain neurons are responsible for transmitting stimuli from the outside world, which involve spouts baking on candle flames, uplink neurons signaling to the central nervous system, and downstream neurons stimulating the arm to remove the fingers from the candle.
A typical neuron is divided into three parts: the cell body, the dendrite, and the axon, which is the center of the neuron, which spreads the transfer process called axons and dendrites to other cells, which usually present a large branch structure, which is thin tinted step by step and thin, which extends to a farther area.
To make a comparable measure, a neuron is about one-tenth the diameter of a human hair, all neurons are electrically excited, and current pulses are mainly processed to reach the cell body and then move along the axon.
The axon acts as a cable, simply transmitting the signal, and once the current pulse reaches the end of the axon, things become more complicated at the synapse position of the neuronaxis.
The key to nerve function is the synaptic signaling process, which is charged and partly chemical. Once the electrical signal reaches the synapse, the neuron releases a special molecule called a neurotransmitter. Next, the neurotransmitter stimulates a second neuron and triggers a new wave of electrical impulses, a mechanism that will be repeated. (Ye Ding Cheng)