The primary objective of this study is to evaluate the safety and tolerability of a single intravenous (IV) and oral (PO) ascending dose of NRX-1074 as evidenced by the incidence and severity of adverse events (AEs), changes in serum chemistry, hematology, and urinalysis, changes in physical examination findings and subject-reported symptoms.

The secondary objectives of this study are to assess the plasma and cerebrospinal fluid (CSF) pharmacokinetics (PK), the oral bioavailability of experimental formulations and the renal elimination through urine concentration of NRX-1074 through 24 hours following dosing.

Randomized, double-blind, placebo-controlled, single ascending dose level study. On Day 1, eligibility of each subject will be confirmed, physical examination will be performed, and blood and urine for laboratories will be obtained. Each subject will be randomized, then will receive either a single IV, SC or IN dose of GLYX-13 or placebo.

Inclusion Criteria:

1. Male and female subjects
2. Aged 18 to 55 years
3. For female subjects, surgically sterile or at least 2 years menopausal, or using an acceptable method of birth control from date of screening to at least 30 days after the last dose of study drugIf of childbearing potential, have a documented negative blood or urine pregnancy test within 24 hours prior to dosing.
4. Clinical laboratory values less than or equal to 2 times the upper limit of normal (ULN) or deemed not clinically significant by the Investigator.
5. Ability to understand the requirements of the study, provide written informed consent, abide by the study restrictions, and agree to return for the required assessments.

Exclusion Criteria: