A Randomized, investigator/subject blind, adaptive, single and multiple ascending dose, placebo-controlled study to investigate safety, tolerability , pharmacokinetics, pharmacodynamics, food effect and taste of RO7017773 following oral administration in healthy participants.

1. Able and willing to provide written informed consent and to comply with the study protocol according to ICH and local regulations.
2. Participants 18 to 55 years of age inclusive, at the time of signing the informed consent.
3. Healthy, as judged by the Investigator. Healthy status will be defined as the absence of evidence of any active or chronic disease following a detailed medical and surgical history, a complete physical examination, vital signs, 12-lead ECG, hematology, blood chemistry, serology and urinalysis.;4. Body mass index (BMI) within the range 18 to 30 kg/m2 (inclusive).
5. Male and female participants
The contraception and abstinence requirements are intended to prevent exposure of an embryo to the study treatment. The reliability of sexual abstinence for male enrollment eligibility needs to be evaluated in relation to the duration of the clinical study and the preferred and usual lifestyle of the participant. Periodic abstinence and withdrawal are not acceptable methods of contraception.
e) Female Participants
A female participant is eligible to participate if she is not pregnant (see Appendix 5), not
breastfeeding, and the following condition applies:
* Women of non-childbearing potential (WONCBP), as defined in Appendix 5 who:
* Have a negative pregnancy test (blood) within the 21 days prior to the first study
drug administration.
f) Male Participants
During the treatment period and for at least 28 days after the last dose of study drug,
agreement to:
* Remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures such as a condom, with partners who are women of childbearing potential (WOCBP, as defined in Section 1 of Appendix 5), or pregnant female partners, to avoid exposing the embryo.
*Refrain from donating sperm 28 days.

1. Any condition or disease detected during the medical interview/physical examination that would render the participant unsuitable for the study, place the participant at undue risk or interfere with the ability of the participant to complete the study, as determined by the Investigator.
2. History or evidence of any medical condition potentially altering the absorption, metabolism or elimination of drugs. This includes a surgical history of the gastrointestinal tract affecting gastric motility or altering the gastrointestinal tract.
3. History of any clinically significant gastrointestinal, renal, hepatic, bronchopulmonary, neurological, psychiatric, cardiovascular, endocrinological, hematological or allergic disease, metabolic disorder, hypofertility, cancer or cirrhosis.
4. Use of any psychoactive medication, or medications known to have effects on CNS or blood flow taken within 4 weeks prior to first dosing (or within 5 times the elimination half-life of the medication) prior to first dosing (whichever is longer).
5. History of convulsions (other than benign febrile convulsions of childhood) including epilepsy, or personal history of significant cerebral trauma or CNS infections (e.g., meningitis).
6. History or current significant ophthalmologic or neurologic condition that would adversely affect the eye movement assessments.
7. A history of clinically significant hypersensitivity (e.g., drugs, excipients) or allergic reactions.
8. Any major illness within one month before the screening examination or any febrile illness within one week prior to screening and up to first study drug administration.
9. Abnormal blood pressure, defined as confirmed (based on the average of >/=3 consecutive measurements) systolic blood pressure (SBP) greater than 140 or less than 90 mm Hg, and diastolic blood pressure (DBP) greater than 90 or less than 50 mm Hg.
10. Abnormal pulse rate, defined as confirmed (based on the average of >/=3 consecutive measurements) resting pulse rate greater than 100 or less than 40 bpm.
11. History or presence of clinically significant ECG abnormalities before study drug administration (e.g. PQ/PR interval >210 ms, QTcF > 450 ms (>470 ms females) or cardiovascular disease (e.g., cardiac insufficiency, coronary artery disease, cardiomyopathy, congestive heart failure, family history of congenital long QT syndrome, family history of sudden death).
12. Clinically significant abnormalities in laboratory test results (including hepatic and renal panels, complete blood count, chemistry panel and urinalysis). In the case of uncertain or questionable results, tests performed during screening may be repeated before randomization to confirm eligibility.
13.ALT and bilirubin > 1.5 X ULN (isolated bilirubin > 1.5 X ULN is acceptable if bilirubin is fractionated and direct bilirubin < 35%).
14. Current or chronic history of liver disease, or known hepatic or biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones).;15. Participants who, in the Investigator's judgment, pose a suicidal or homicidal risk, or any participant with a history of suicidal or homicidal attempts.
16. Have used or intend to use over-the-counter or prescription medication including herbal medications within 30 days prior to dosing.
17. Participants likely to need concomitant medication during the study period (including for dental conditions).
18. Participation in an investigational drug or device study within 90 days prior to screening, as calculated from the day of follow-up from the previous study, or more than 4 times a year.
19. Positive test for drugs of abuse or alcohol.
20. For, female participants, a positive pregnancy test.
21. Show evidence of human immunodeficiency virus (HIV) infection and/or positive human HIV antibodies.
22. Positive result on hepatitis B (HBV) or hepatitis C (HCV), presence of hepatitis B surface antigen (HBsAg) or positive hepatitis C antibody test result at screening or within 3 months prior to starting study treatment.
23. Dietary restrictions that would prohibit the consumption of standardized meals.
24. Consumption of any prohibited medications and food before study start and during the study.
25. Any suspicion or history of alcohol abuse and/or suspicion of regular consumption of drug of abuse or previous history of or treatment for a dependence disorder.
26. Sensitivity to any of the study treatments, or components thereof, or drug or other allergy that, in the opinion of the Investigator, contraindicates the participation in the study.
27. Participants who regularly smoke more than 5 cigarettes daily or equivalent and unable or unwilling not to smoke during the in-house period.
28. Participants who have donated over 500 mL of blood or blood products or had significant blood loss within 3 months prior to screening.
29. Participants under judicial supervision, guardianship or curatorship.
30. Contraindications for MRI scans (including but not restricted to claustrophobia, pacemaker, artificial heart valves, cochlear implants, presence of foreign metal objects in head or body, intracranial vascular clips, etc.) or any brain/head abnormalities restricting MRI eligibility. Any sensorial impairment such as deafness and reduced visual acuity which cannot be corrected in the fMRI scanner.
31. Contraindication to TMS-EEG (including, but not restricted to, a history of epilepsy or febrile seizures, having metal objects in brain or skull, having a cochlear implant or implanted deep brain stimulator, abnormal sleeping pattern (e.g., working night shifts), resting motor threshold (rMT) of more than 83% of the maximum stimulator output as measured using TMS-EMG during screening.
32. Fulfillment of any of the MRI contraindications on the standard radiography screening questionnaire.