Effect of Transcranial Alternative Current Stimulation at Alpha Frequency (α-tACS) on Stressed Healthy Subjects

Healthy Clinical Trial

— CAF-TAS  

Official title:

Biological, Neuropsychological and Electrophysiological Effect of Transcranial Alternative Current Stimulation at Alpha Frequency (α-tACS) on Stressed Healthy Subjects

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06229002
• Other study ID #: 2023-A01368-37
• Status: Recruiting
• Phase: N/A
• Start date: January 24, 2024
• Est. completion date: February 1, 2028

Study information

• Verified date: December 2023
• Source: Hôpital le Vinatier
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

stress. Notably, several studies reported that stress could alter impulsivity, source monitoring, and time perception.

Several mechanisms are involved in the response to a stress factor, among them the hypothalamic-pituitary-adrenal (HPA) axis. The cortisol reactivity (it means the cortisol secretion after the exposure to a standardized stress factor) is a reliable tool to assess the function of HPA. Cortisol secretion is bidirectionally influenced by the prefrontal cortex (PFC), which is involved in the expression and regulation of stress as well. The asymmetry of the alpha band (AFα) is a well known electrophysiological parameter to assess the function of PFC. More precisely, AFα is arising a growing interest, as it is believed to be correlated with the cortisol reactivity. Modifying this asymmetry could influence the stress response.

Transcranial Alternating Current Stimulation (tACS) consists in delivering a sinusoidal alternating current between two electrodes placed on the scalp at a predefined frequency. Previous studious reported that tACS, if delivered at the alpha frequency, increased the alpha band in the stimulated areas

Description:

The study will focus on the effect of tACS at alpha frequency (α-tACS), delivered on the dorsolateral prefrontal cortex, on the response to a stress factor.

In this study, while receiving a single α-tACS session, the participants will complete a standardized stress test combining cognitive stress (mental calculation) and physical stress (cold pressure): the Maastricht Acute Stress Test. The main objective aims at assessing the effect of a single session of tACS at alpha frequency, delivered on the dorsolateral prefrontal cortex, on the cortisol reactivity in healthy stressed subjects. In that study, the influence of α-tACS on other biological ; electrophysiological, neuropsychological parameters relevant for the stress response will be assessed also.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 40
• Est. completion date: February 1, 2028
• Est. primary completion date: February 1, 2027
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 45 Years

Eligibility

Inclusion Criteria:

• Right-handed Men and Women aged between 18 and 45

• If woman, hormonal contraception required

• Having given their written informed consent

• Affiliated with a social security scheme

• French speakers and readers

Exclusion Criteria:

• Contraindication to the exposure to exposure to tACS

• Current psychiatric disorder as classified in the DSM-5

• Regular intake of any psychotropic drug or Beta Blocker

• Recent exposure to a traumatic event

• Any debilitating condition making the experimental procedure not feasible

• Pregnancy

Related Conditions & MeSH terms

• Healthy

Intervention

Procedure:
• Transcranial alternative current stimulation (tACS) at alpha frequency
Single session of tACS
• Sham stimulation
Single session of tACS sham stimulation

Locations

Country	Name	City	State
France	Centre Hospitalier Le Vinatier	Bron	Aura

Sponsors (1)

Lead Sponsor	Collaborator
Hôpital le Vinatier

Country where clinical trial is conducted

France, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Area under the curve (AUC) of the cortisol secretion after the stress task.	Samples of salivary cortisol will be repeatedly (10 occurences) collected during the experiment. The collection will take place before, during and after the stress task.	1 day
Secondary	Effect of a-tACS on the cortisol awakening response in stressed healthy subjects	Samples of morning salivary cortisol will be collected repeatedly (3 times) before experimental session (including the stress task and the tACS session). A last sample of morning salivary cortisol will be collected the following day	4 days
Secondary	Effect of a-tACS on the molecular reactivity to stress	The expression level of different proteins implicated in the intracellular communication channel after the couple cortisol-glucocorticoid receptor was formed (namely : NR3C1) will be assessed. A blood sample will be collected and the expression level of the relevant genes will be assessed by qPCR	1 day
Secondary	Effect of a-tACS on the molecular reactivity to stress	The expression level of different proteins implicated in the intracellular communication channel after the couple cortisol-glucocorticoid receptor was formed (namely : FKBP4) will be assessed. A blood sample will be collected and the expression level of the relevant genes will be assessed by qPCR	1 day
Secondary	Effect of a-tACS on the molecular reactivity to stress	The expression level of different proteins implicated in the intracellular communication channel after the couple cortisol-glucocorticoid receptor was formed (namely : FKBP5) will be assessed. A blood sample will be collected and the expression level of the relevant genes will be assessed by qPCR	1 day
Secondary	Effect of a-tACS on the molecular reactivity to stress	The expression level of different proteins implicated in the intracellular communication channel after the couple cortisol-glucocorticoid receptor was formed (namely : BAG1) will be assessed. A blood sample will be collected and the expression level of the relevant genes will be assessed by qPCR	1 day
Secondary	Effect of a-tACS on the molecular reactivity to stress	The expression level of different proteins implicated in the intracellular communication channel after the couple cortisol-glucocorticoid receptor was formed (namely : PTGES3) will be assessed. A blood sample will be collected and the expression level of the relevant genes will be assessed by qPCR	1 day
Secondary	Effect of a-tACS on the molecular reactivity to stress	The expression level of different proteins implicated in the intracellular communication channel after the couple cortisol-glucocorticoid receptor was formed (namely : HSP90AA1) will be assessed. A blood sample will be collected and the expression level of the relevant genes will be assessed by qPCR	1 day
Secondary	Effect of a-tACS on the molecular reactivity to stress	The expression level of different proteins implicated in the intracellular communication channel after the couple cortisol-glucocorticoid receptor was formed (namely : HSPA1A) will be assessed. A blood sample will be collected and the expression level of the relevant genes will be assessed by qPCR	1 day
Secondary	Effect of a-tACS on the asymmetry of the alpha band (AFa) in stressed healthy subjects	AFa refers to the average difference in alpha-band activity (typically8-13 Hz) between the left and right frontal areas (F3- F7 versus F4-F8, respectively). For a 5-minute block, AFa will be assessed by EEG recording while the participant is at resting state and only requested to alternatively open and close the eyes, according to a standardized procedure	1 day
Secondary	Effect of a-tACS on the beta band in stressed healthy subjects	The participant will have to complete the Kirby Delay Discounting Task (DDT). Subjects are presented with a series of hypothetical choices of amount of reinforcer to be had instantaneously, and a larger reinforcer available after a fixed delay. (For example : "Would you prefer 37€ today or 80€ in 60 days?" The outcome will be the change in the number of immediate choices between before and after the stress period (?DDT) express in percent	1 day
Secondary	Effect of a-tACS on source monitoring in stressed healthy subjects	Source monitoring refers to the cognitive processes involved in making attributions about the origins of mental experiences (for example : was this mental experience dreamt?, imagined?, really perceived? If this was perceived, was it produced by myself or by anybody else?". Two subtypes of source monitoring will be tested : the reality monitoring (RM) and the internal monitoring (IM). In each task the participant will be confronted with a list of words he/she will have to determine the source of. The outcome will be the proportion of false attributions, expressed in percent	1 day
Secondary	Effect of a-tACS on impulsivity in stressed healthy subjects	The participant will have to complete the Kirby Delay Discounting Task (DDT). Subjects are presented with a series of hypothetical choices of amount of reinforcer to be had instantaneously, and a larger reinforcer available after a fixed delay. (For example : "Would you prefer 37€ today or 80€ in 60 days?") The outcome will be the change in the number of immediate choices between before and after the stress period (?DDT) express in percent	1 day
Secondary	Effect of a-tACS on time perception in stressed healthy subjects	time perception refers to how the brain represents the temporal structure of events and of our environment. This ability can be assessed through different experimental designs. In this protocol, the participants will complete a time reproduction task, consisting in tapping at a defined frequency (1Hz) with a push-button. After a training phase (pressing the push-button while being guided), the participant will have to produce the same rhythm on his own. The outcome will be the mean difference between the reference interval (1s) and the time intervals executed by the participant, express in milliseconds	1 day