Induction and Stabilization of Gamma Oscillations With 40 Hz External Brain Stimulation

Summary

The goal of the present studies is to develop and validate novel stimulation protocols for the entrainment of gamma oscillations, which are associated with many cognitive functions and critically involved in cognitive impairment such as Alzheimer's disease. In this proposal, combination of repetitive transcranial magnetic stimulation (rTMS) and transcranial alternating current stimulation (tACS), which has been shown effective for the induction, and stabilisation of alpha and theta frequencies in our forgoing studies, will be adopted to the gamma frequency range and applied on prefrontal regions as well as model-based cortical areas to enhance and stabilize gamma oscillations, thereby facilitating cognition

Conditions

• Alzheimer Disease
• Working Memory
• EEG Brain Oscillations

Interventions

DEVICE

Transcranial alternating current stimulation

Transcranial alternating current was delivered utilizing a Starstim 8-channel constant current, battery-powered electric stimulator (Neuroelectrics, Barcelona, Spain). Circular carbon rubber electrodes (2cm radius, 12,57 cm2) were used throughout the stimulation. Before placing the electrodes on the head, the subject's hair was moved to the side

DEVICE

Theta burst stimulation

the intermittent theta burst stimulation (iTBS) which is regarded as safe for high-frequency neuromodulation. Compared to classical rTMS, where pulses are applied repeatedly at a fixed frequency, iTBS consists of bursts of pulse triplets. In the classical protocol, the bursts are applied for two seconds in 5Hz intervals followed by an eight-second break, before the next bursts are applied. This pattern is repeated for 190 seconds resulting in 600 pulses per protocol.

DEVICE

Sham (No Treatment)

In the case of sham TMS, two different sham coils (double 70mm pCool-SHAM coil, Mag\&More GmbH, Munich, Germany) will produce audible clicks at the decibel intensity corresponding to an active coil without the induction of an electromagnetic pulse. Sham tACS will be applied by only ramping the current for 15 seconds up and 15 seconds down at the beginning and end of the stimulation respectively.

Sponsors & Collaborators

• Leibniz Research Centre for Working Environment and Human Factors

  collaborator OTHER

• The National Brain Mapping Laboratory (NBML)

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2021-07-13

Primary Completion

2023-11-30

Completion

2023-11-30

Countries

• Germany

Study Locations