How does sensorimotor mu rhythm activity impact corticospinal output during TMS delivery?

Sensorimotor mu rhythm activity plays a significant role in influencing corticospinal output during transcranial magnetic stimulation (TMS) delivery. The sensorimotor mu rhythm is an oscillatory brain activity that occurs in the frequency range of 8-13 Hz and is predominantly observed over sensorimotor cortical regions. Here is how sensorimotor mu rhythm activity impacts corticospinal output during TMS delivery:

1. Phase-Dependent Effects: Studies have shown that the phase of the sensorimotor mu rhythm can influence corticospinal excitability. Specifically, corticospinal output is modulated by the phase of the mu rhythm, with increased excitability observed during specific phases of the mu rhythm cycle. For example, corticospinal output tends to be higher during the trough (negative peak) phases of the mu rhythm compared to the peak (positive peak) phases.

2. Enhancement vs. Suppression: When TMS is delivered to the primary motor cortex (M1) during the trough phases of the mu rhythm, it can lead to enhanced corticospinal transmission and improved motor learning. In contrast, TMS delivered during the peak phases of the mu rhythm may result in weaker corticospinal transmission and have less impact on motor learning. This phase-dependent effect highlights the importance of timing TMS interventions based on the ongoing sensorimotor mu rhythm activity.

3. Interhemispheric Communication: In addition to influencing corticospinal output, sensorimotor mu rhythm activity also affects interhemispheric communication between homologous motor cortex regions. Studies have demonstrated that the phase synchronicity of the mu rhythm can determine the efficacy of communication between motor cortices, further emphasizing the role of mu rhythm activity in shaping neural interactions.

4. Complex Interplay: The interplay between sensorimotor mu rhythm phase and power is complex and interdependent in shaping corticospinal tract activity. Both the phase and power of the mu rhythm contribute to modulating corticospinal output, highlighting the need to consider both aspects when utilizing TMS for measurement or interventional purposes.

In conclusion, sensorimotor mu rhythm activity exerts a significant influence on corticospinal output during TMS delivery, with phase-dependent effects playing a crucial role in modulating neural excitability and motor learning processes. Understanding and leveraging the impact of mu rhythm activity can enhance the efficacy of TMS interventions and provide insights into the mechanisms underlying motor control and plasticity in the human brain.

Hussain, S. J., Claudino, L., Bönstrup, M., Norato, G., Cruciani, G., Thompson, R., ... Cohen, L. G. (2019). Sensorimotor oscillatory phase–power interaction gates resting human corticospinal output. Cerebral Cortex, 29(9), 3766–3777. https://doi.org/10.1093/cercor/bhy255.

Comments

Bipolar Montage Description of a Focal Discharge

In a bipolar montage depiction of a focal discharge in EEG recordings, specific electrode pairings are used to capture and visualize the electrical activity associated with a focal abnormality in the brain. Here is an overview of a bipolar montage depiction of a focal discharge: 1. Definition : o In a bipolar montage, each channel is created by pairing two adjacent electrodes on the scalp to record the electrical potential difference between them. o This configuration allows for the detection of localized electrical activity between specific electrode pairs. 2. Focal Discharge : o A focal discharge refers to a localized abnormal electrical activity in the brain, often indicative of a focal seizure or epileptic focus. o The focal discharge may manifest as a distinct pattern of abnormal electrical signals at specific electrode locations on the scalp. 3. Electrode Pairings : o In a bipolar montage depicting a focal discharge, specific elec...

Frontal Arousal Rhythm

Frontal arousal rhythm is an EEG pattern characterized by frontal predominant alpha activity that occurs in response to arousal or activation. 1. Definition : o Frontal arousal rhythm is a specific EEG pattern characterized by alpha activity predominantly in the frontal regions of the brain. o It is typically observed in response to arousal, attention, or cognitive engagement and may reflect a state of increased alertness or readiness. 2. Characteristics : o Frontal arousal rhythm is characterized by alpha frequency activity (typically between 7-10 Hz) with an amplitude ranging from 10 to 50 μV. o This pattern is often transient, lasting up to 20 seconds, and may occur in response to external stimuli, cognitive tasks, or changes in the environment. 3. Clinical Significance : o Frontal arousal rhythm is considered a normal EEG pattern associated with states of arousal, attention, or cognitive processing. o ...

Review Settings of EEG

The review settings of an EEG recording refer to the parameters that can be adjusted to optimize the visualization and interpretation of electrical brain activity. Here is an overview of the key review settings in EEG analysis: 1. Amplification (Gain/Sensitivity) : o Definition : Amplification, also known as gain or sensitivity, determines how much the electrical signals from the brain are amplified before being displayed on the EEG recording. o Measurement : Typically measured in microvolts per millimeter (μV/mm). o Impact : Adjusting the amplification setting can affect the visibility of high-amplitude and low-amplitude activity. High-amplitude activity may require vertical compression to fit within the display range, while low-amplitude activity may require lower sensitivity settings for better visualization. 2. Frequency Filtering : o Bandpass : The frequency range within which EEG signals are analyzed. Common settings include ...

Empirical Research

Empirical research is a type of research methodology that relies on observation, experimentation, or measurement to gather data and test hypotheses or research questions. Empirical research is characterized by its emphasis on collecting and analyzing real-world data to draw conclusions, make predictions, or validate theories based on evidence obtained through direct observation or experience. Key features of empirical research include: 1. Observation and Measurement : Empirical research involves the systematic observation and measurement of phenomena in the real world. Researchers collect data through direct observation, experiments, surveys, interviews, or other methods to gather empirical evidence that can be analyzed and interpreted. 2. Data Collection : Empirical research focuses on collecting data that is objective, verifiable, and replicable. Researchers use structured data collection methods to gather information that can be quant...

Genetic Development Disorders

Genetic developmental disorders are conditions that arise from abnormalities in an individual's genetic makeup and can impact various aspects of development, including physical, cognitive, and behavioral domains. 1. Definition: Genetic developmental disorders are conditions that result from genetic mutations or abnormalities in the individual's DNA. These disorders can affect the normal development and functioning of various bodily systems, leading to a wide range of physical, cognitive, and behavioral symptoms. 2. Causes: Genetic developmental disorders are caused by alterations in the individual's genetic material, which can be inherited from parents or occur spontaneously due to new mutations. These genetic changes can disrupt normal developmental processes, leading to structural, functional, or regulatory abnormalities in the body. 3. Types of ...

Mashtishk Vigyan Anusandhan

Search This Blog