A new study suggests that restoring Gamma wave impulses in the olfactory bulb may aid in the treatment of depression.
The study, which was published online on May 9 in the journal Neuron, focuses on the role of neurons in transmitting information through electrical signals. Recent research has shown that communication between different brain regions requires synchronized activity patterns in groups of neurons, which involves oscillations of joint silence and activity.
Investigating the Link between Gamma Patterns
Altered gamma signals originating from the olfactory bulb and transmitting to other areas of the limbic system, such as the piriform cortex and hippocampus, may exert an influence on emotions.
The exact cause of these changes remains unclear; however, they could potentially be triggered by factors such as infections, stress, or medication.
According to a particular hypothesis, depression may arise due to modifications in the gamma patterns that travel from the olfactory bulb to other regions of the brain.
In the conducted study, researchers employed a device to record and transmit gamma oscillations from the olfactory bulb to the brains of rodents using closed-loop electrical stimulation.
The device had the capability to either suppress or amplify gamma oscillations. In healthy animals, the device successfully suppressed the oscillations.
Conversely, animals with suppressed gamma oscillations exhibited behaviors resembling those observed in humans with depression.
Furthermore, the research team discovered that by reintroducing an amplified olfactory bulb signal back into the brains of depressed rats, the normal gamma function of the limbic system was restored, leading to a reduction in depressive behaviors by nearly 40% toward a level comparable to that of normalcy.
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Potential Treatment Approach for Depression
A repeating pattern that occurs approximately 30 times per second and is important in timing complex information processing is called “Gamma rhythm”, including emotional responses.
Previous studies suggest changes in gamma oscillations could be an electrophysiological marker of depression in brain regions associated with the sense of smell, which are also connected to emotions.
The researchers used genetic and cell signaling techniques to disable olfactory bulb function in rodents and observed an increase in depression-like behavior. They then reversed these behaviors using a device that amplified gamma signals in the brain at their natural pace.