Modulation of Memory Consolidation in Humans

Sleep Clinical Trial

Official title:

Modulation of Memory Consolidation in Humans

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04714879
• Other study ID #: MemorySFB
• Status: Completed
• Phase: N/A
• Start date: December 1, 2018
• Est. completion date: January 31, 2021

Study information

• Verified date: June 2024
• Source: University Medicine Greifswald
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The goal of the present study is to optimize effects of slow oscillatory transcranial direct current stimulation (so-tDCS) on sleep physiology and memory consolidation in humans by combining computational and experimental human models in an iterative process. The investigator therefore works in cooperation with Prof. Dr. Klaus Obermayer (TU Berlin), who contributes computation models with the aim to mechanistically understand the impact of different perturbations on sleep-related electrophysiological features, and to subsequently optimize so-tDCS parameters for inducing SO and spindle activity.

Description:

Sleep plays an active role in long-term consolidation of memories. Specifically, slow oscillations (SO, large amplitude waves <1 Hz) and sleep spindles (8-15 Hz), that can be measured by electroencephalography (EEG), appear to be critical for declarative memories. According to the "active system consolidation" account, newly encoded memories are reactivated during sleep, accompanied by sharp-wave ripple events (80-100 Hz) in the hippocampus, and redistributed to cortical long-term storage networks through a coordinated dialog between the hippocampus and neocortex. This dialog is supposedly mediated by a particular coupling between cortical SO and thalamo-cortical fast spindles (12-15 Hz), with spindles preferably occurring during SO up-phases, and hippocampal ripples grouped at the troughs of fast spindles. Slow spindles (8-12 Hz) are a separate kind of sleep spindle activity whose function in memory consolidation is less well understood. Interventions targeting sleep parameters may not only make it possible to beneficially modulate a vital aspect of memory consolidation, i. e., sleep-dependent memory consolidation, but may also help to delineate which specific elements of the neural dynamics during sleep are crucial for successful consolidation.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 54
• Est. completion date: January 31, 2021
• Est. primary completion date: January 5, 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 50 Years to 80 Years

Eligibility

Inclusion Criteria:

• Adults aged between 50-80 years
• screened as healthy in a structured telephone interview

Exclusion Criteria:

• Mini Mental Status Examination scores below 24
• history of severe untreated medical, neurological, and psychiatric diseases
• sleep disorders
• alcohol or substance abuse
• brain pathologies identified on MRI scan
• intake of medication acting primarily on the central nervous system (e.g., antipsychotics, antidepressants, benzodiazepines, or any type of over-the-counter sleep-inducing drugs such as valerian),
• nonfluent German language abilities.

Related Conditions & MeSH terms

• Sleep

Intervention

Other:
• Device: anodal tDCS
anodal current modulated by an oscillatory component including a fixed (0,75 Hz) versus individually adapted so-tDCS frequency with three different stimulation durations (5 min, 2 min, 30 sec)
• Device: no stimulation
sham stimulation

Locations

Country	Name	City	State
Germany	University medicine Greifswald	Greifswald

Sponsors (2)

Lead Sponsor	Collaborator
University Medicine Greifswald	Technische Universität Berlin

Country where clinical trial is conducted

Germany, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Changes in EEG power (µV²) of the slow oscillation frequency band (0.5-1 Hz) following so-tDCS during sleep	Investigation whether 7 different protocols of anodal tDCS (including SHAM) lead to distinct changes in slow oscillation power	up to 20 weeks
Primary	Changes in EEG power (µV²) of the sleep spindles frequency band (12-15 Hz) following so-tDCS during sleep	Investigation whether 7 different protocols of anodal tDCS (including SHAM) lead to distinct changes in sleep spindle power	up to 20 weeks
Primary	Changes in cross-frequency coupling (resultant vector length) between slow oscillations and sleep spindles following so-tDCS during sleep	Investigation whether 7 different protocols of anodal tDCS (including SHAM) lead to distinct changes in coupling between slow oscillations and sleep spindles	up to 20 weeks
Secondary	Sleep architecture	Proportion of time spent in different sleep stages (in %) during the entire nap and following so-tDCS	up to 20 weeks
Secondary	Changes in EEG power (µV²) of the delta frequency band (1-4 Hz) following so-tDCS during sleep	Investigation whether 7 different protocols of anodal tDCS (including SHAM) lead to distinct changes in delta power	up to 20 weeks