Losartan Modulates Neural Responses to Looming Visual Stimuli: An Eye-tracking Study

Not Applicable

Recruiting

• Conditions: Healthy
• Interventions: Drug: Losartan; Drug: Placebo

• Registration Number: NCT06329076
• Lead Sponsor: University of Electronic Science and Technology of China

Brief Summary

The main aim of the present study is to investigate the effects of orally administered losartan on the perception of time-to-collision of threatening and non-threatening stimuli by combining a validated looming fear eye-tracking paradigm with a randomized between-subject placebo-controlled pharmacological trial design.

Detailed Description

Animal models and initial findings in humans suggest a role of the angiotensin II antagonist losartan in socio- emotional processes. At the same time, the visual system's remarkable ability to perceive and interpret impending threats, notably through the "looming" phenomenon- a distinct pattern of optical expansion on the retina as objects approach, theoretically allows for precise estimation of the time-to-collision (TTC). It was demonstrated that the affective content of looming stimuli influences perceived TTC, with threatening objects judged as approaching sooner than non-threatening objects, hinting at a nuanced interaction between emotional valence and temporal perception. Within this context the present study aims to examine whether angiotensin II blockade via Losartan modulates the perception of time-to-collision towards threatening and non-threatening stimuli. To this end, healthy individuals will undergo a double-blind, between-subjects, placebo-controlled pharmaco-eye-tracking experiment and receive a single oral dose of losartan (50 mg) or placebo before performing a looming fear task 90 minutes after administration. The task paradigm will encompass threatening (butterfly, rabbit) and non-social (spider, snake) stimuli to examine the emotion-specific effects of losartan.

Study Timeline

• Study Start: 2024-03-05
• Study First Submitted: 2024-03-15
• Study First Submitted QC: 2024-03-15
• Study First Posted: 2024-03-25
• Status Verified: 2024-04
• Last Update Submitted: 2024-04-09
• Last Update Posted: 2024-04-11
• Primary Completion: 2025-06-01
• Study Completion: 2025-07-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 80

Inclusion Criteria

• Healthy subjects who volunteer to participate and are able to fully understand and agree with this study by written informed consent.
• Normal or corrected-normal version

Exclusion Criteria

• History of neuropsychiatric diseases.
• History of cardiac disease, including arrhythmias, aortic stenosis, or congestive heart failure; history of syncope or unexplained loss of consciousness.
• History of hepatic diseases, including cholestasis, biliary obstructive disease, or severe liver dysfunction.
• History of renal diseases, including renal stones or renal failure.
• History of hyponatremia(Serum sodium <135mmol/L) or hyperkalemia (Serum potassium>5.5mmol/L); history of diabetes mellitus or diabetes insipidus
• Known hypersensitivity or allergic reaction to any medication or hormone; strong allergic reaction to food.
• Infections such as COVID-19 or influenza, or unexplained fever.
• Subjects with hypertension (BP ≥130/80mmHg) or hypotension (BP ≤ 90/60mmHg).
• History of alcohol or drug abuse; smoker (≥ 10 cigarettes or ≥ 3 cigars or ≥ 3 pipes/day); smoker using e-cigarettes.
• Blood donation (≤ 1 month prior to administration).
• Take oral contraceptives or receive hormonal medications in the three months prior to the experiment.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Losartan group	Losartan	Drug:Losartan
Placebo group	Placebo	Drug: Placebo

Primary Outcome Measures

Name	Time	Method
Ratio of judged-time-to-collision to actual-time-to-collision for threatening versus non-threatening stimuli after losartan administration	120 minutes - 150 minutes after treatment	Comparison of the ratio between the judged time to collision and the actual time to collision between the treatment groups for threatening (spider, snake) and non-threatening (rabbit, butterfly) stimuli.

Secondary Outcome Measures

Name	Time	Method
First saccade latency(ms) for threatening versus non-threatening stimuli after losartan administration	120 minutes - 150 minutes after treatment	Comparison of first saccade latencies between treatment groups for threatening (spider, snake) and non-threatening (rabbit, butterfly) stimuli.
Fixation duration(ms) for threatening versus non-threatening stimuli after losartan administration	120 minutes - 150 minutes after treatment	Comparison of mean fixation durations between treatment groups for threatening (spider, snake) and non-threatening (rabbit, butterfly) stimuli.

Trial Locations

Locations (1)

University of Electronic Science and Technology of China; 🇨🇳 Chengdu, Sichuan, China