Stanford University tests “brain chip for weight loss” and electrifies you whenever you want to eat.


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Recently, six morbidly obese patients participated in a special weight-loss experiment at Stanford, in which chips were implanted into the brain to eliminate greed. When they want to eat, the chip discharges properly, eliminating the desire to eat.
Can’t you keep on losing weight? Try this chip.
“Can’t hold your tongue” may be a very painful thing in the process of losing weight. A recent Stanford University study has controlled this problem from its roots: chips implanted into the brain, eliminating greed!
Six morbidly obese patients agreed to participate in the clinical trial. They volunteered to test a new brain chip that stimulates their brains when they want to overeat.
The chip, called the Reactive Nerve Stimulation System (RNS), was developed by NeuroPace, a medical technology company. The aim is to help patients with epilepsy. Once implanted into the brain, it tracks brain activity and constantly monitors how the brain works.
However, a recent study published in the Proceedings of the National Academy of Sciences (PNAS) suggests that the same technology can also be used to prevent overeating patterns.
In the next five years, six people will implant RNS chips in their brains for 18 months. To meet the requirements of this study, participants had a body mass index of more than 45 and did not lose weight through gastric bypass surgery or cognitive behavioral therapy.
That is to say, adults with a height of 170 cm need to weigh more than 130 kilograms before they can participate in the experiment.
The chip has been successfully tested in mice. The device is embedded in the nucleus accumbens (NAc) of the brain and is closely related to food intake.
Electrical stimulation of rats can effectively control appetite and is expected to treat obesity symptoms.
As mentioned above, this experiment has been successfully tested in mice.
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In this study, researchers recorded local field potentials from NAc (nucleus accumbens) in mice, and found that 1-4Hz oscillating power could effectively trigger nerve stimulation, thereby reducing the feeding behavior of mice.
In the course of the study, similar oscillations occurred in human NAC, so researchers believe that this method can be used in human beings to try and control some diseases.
Impulsiveness is one of the most common and disabling characteristics of many brain diseases.
During the expected incentive period, the increased responsiveness of NAC is prone to impulsive behavior, which may have a serious impact on the development of maladaptive behavior.
It is noteworthy that electrophysiology, neurochemistry and functional neuroimaging have been demonstrated in a number of studies during the expected short window period. These correlations may provide time-sensitive interventions for treatment.
Recently, a reactive nerve stimulation (RNS) system has been approved by the Food and Drug Administration for adjuvant treatment of partial epilepsy.
This intracranial closed-loop system has been proved to be able to detect epileptic-like activity and prevent the transmission of epilepsy by responsively transmitting electrical stimulation directly to the epileptic seizure area.
Here, we study the possibility of RNS intervention before receiving high-return stimulus. Considering the availability of the system, this work has direct transformation potential.
Researchers found that NAC, which stimulates mice, expects food rewards to effectively reduce overeating. However, in order to use the automatic stimulus system to “close the cycle”, the identification, characterization and improvement of biomarkers are expected to be the key follow-up steps.
Experiments and results
Delta-Range field potential increased earlier than gluttony in mouse NAc
The multi-electrode array was implanted into mouse NAc, as shown in Fig. 1A-D. After a week of convalescence, the mice were exposed to high fat (HF) for an hour a day, a program known to induce overeating.
Based on previous reports of changes in the discharge of different types of NAc cells during the expected reward period, mice were recorded daily NAc LFPs 2 hours, 1 hour and 1 hour before exposure to HF food. All mice reached a stable overeating standard on the 10th day. The power spectral density of NAc LFPs in mice was analyzed on day 0 and 10 before HF intake.
Figure 1: An overview of animal experimental schematics, histology, electrode design, and high fat (HF) intake. (A) The schematic design of the experiment, the location of the implanted electrode; (B-D) histological examination showing the implant location, the design of multi-electrode array of eight contact points, six of which are designated recording contacts (blue/green), two are designated stimulating contacts (red); (E-G) 1 hour HF exposure per day, 10 There was a steady overeating behavior during the day, manifested by a significant increase in daily HF intake.
As a control, the same analysis was performed immediately before the mice ate standard food (Fig. 2A – c).
Figure 2: The original local field potential (LFPs), power spectral density, time-frequency analysis of nucleus accumbens (NAc) LFPs, pulse power characterization, RNS setup system block diagram.
As shown in the above video, Delta-band activity in NAc was detected immediately before HF ingestion in mice.
The strongest change in LFPs is the increase in power in the very low frequency delta oscillation (Fig. 2D – H) after a heavy eating on the 10th day before HF intake.
In conclusion, these results suggest that in overeating mice, the increase in delta power in LFP recorded by NAc occurs before HF intake, and therefore may be a useful biomarker for triggering RNS.
Delta oscillation as a biomarker of RNS

Figure 3: Diagram of the intervening period during 1 hour of high fat (HF) exposure in mice, and the results of HF intake by different electrical stimulation schemes.
As shown in the video below, RNS triggered by delta-band activity successfully inhibited mice’s eating behavior similar to gluttony. The red dotted line in the power spectrum represents the power threshold for triggering RNS.
FMRI activity and Delta oscillation of human NAc during the reward expectation period
Because there is no food reward in the operating room, we can only induce the expectation of money reward through a well-developed neuroimaging task.
In each mid-task test, participants were given a visual cue indicating that they would receive or avoid losing a clear monetary reward (reward or punishment).
This task allows researchers to distinguish between different stages of reward processing, including reward expectations and outcomes, as shown in Figure 5.
Fig. 5: Diagrams of functional neuroimaging and local field potential (LFP) recorded during the monetary incentive delay (MID) task in human subjects.
The findings provide preliminary evidence that RNS has the potential to treat intractable behavioral disorders that were not previously thought to be treatable by neurosurgical procedures, including eating disorders, even obesity and addiction, the researchers said.
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