A Study to Explore Pharmacodynamic Effects of BIIB104 on Brain Circuitry in Healthy Participants

A Phase 1, Randomized, Double-Blind, Placebo-Controlled, 2-Period, 2-Sequence Crossover Study to Explore Pharmacodynamic Effects of BIIB104 on Brain Circuitry Using BOLD Functional MRI and Arterial Spin Labeling in Healthy Participants

The primary objective of the study is to explore the pharmacodynamic (PD) effects of BIIB104 on brain circuitry associated with emotional processing in healthy participants.

The secondary objectives of the study are to evaluate the safety and tolerability of BIIB104 in healthy participants; To further explore the PD effects of BIIB104 on brain circuitry associated with emotional processing in healthy participants; To explore the PD effects of BIIB104 on brain circuitry associated with working memory in healthy participants using the N-Back; To explore the PD effects of BIIB104 on regional cerebral blood flow (CBF) in healthy participants; To explore the PD effects of BIIB104 on brain circuitry during resting state in healthy participants.

Key Inclusion Criteria:

• Have a body mass index (BMI) between 18 and 30 kilogram per meter square (kg/m^2), inclusive.
• Right-handed as determined by the Edinburgh Handedness Inventory (score of >40) [Oldfield 1971].

Key Exclusion Criteria:

• Previous participation in this study or previous studies with BIIB104.
• Body weight <55 kg.
• History of severe allergic or anaphylactic reactions, or systemic hypersensitivity reaction to BIIB104 or any allergic reactions that in the opinion of the Investigator are likely to be exacerbated by any component of the study treatment.

NOTE: Other protocol defined inclusion/exclusion criteria may apply.