Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Biodistribution & persistence
High brain penetration; brain:plasma ratio 2.23 (mouse) and 3.22 (rat)
“The brain to plasma ratio of zuranolone was 2.23 after IP injection (1 mg/kg) (SSN-868) in male mice and 3.22 (Study No. SSN-01237) after oral administration in male rats.”
CNS: convulsions and deaths in dogs, including after dosing stopped
“Deaths, convulsions, and increased severity of clinical signs occurred in some dogs prior to a scheduled daily dose or some period after the previous dose (e.g., during a dosing holiday or recovery period after the end of dosing).”