Single and Multiple Ascending Dose and Food Effect PK Study in Healthy Adult and Elderly Subjects

Inclusion Criteria: * Healthy as determined by the Investigator, based on a medical evaluation including medical history physical examination, neurological examination, laboratory tests and cardiac monitoring * Men, age 18-54 years inclusive at Screening (Part 1) or men and postmenopausal or surgically sterile women age 55-80 Exclusion Criteria: * Any history of major psychiatric disorders, including substance use disorders, according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria. * Acute suicidality or history of suicidal behavior. * Alanine aminotransferase or aspartate aminotransferase levels greater than 1.5 times the upper limit of normal (ULN) at Screening. One retest is allowed. * A corrected QT interval measurement corrected according to the Fridericia rule (QTcF) \> 450 msec during controlled rest at screening or between screening and first dose administration, or family history of long QT syndrome. * Any clinically significant abnormalities in rhythm, conduction, or morphology of the resting ECG and any abnormalities in the 12-lead ECG that, in the judgement of the Investigator or Medical Monitor, may interfere with the interpretation of QTc interval changes, including abnormal ST-T-wave morphology or left ventricular hypertrophy. * A clinically significant vital signs abnormality at screening or between screening and first dose administration. This includes, but is not limited to, the following, in the supine position: (a) systolic blood pressure \< 90 or \>150 mmHg, (b) diastolic blood pressure \<50 or \> 95 mmHg, or (c) heart rate \< 45 or \>100 beats per minute.