Acetylcholinesterase (AChE) and gamma-aminobutyrate transaminase (GABA-T) were localized in organized cultures of rat embryo spinal cord. AChE was seen in neurones of the ventral horn and intermediate nucleus and in the dorsal horn neuropil. AChE was also present on the soma membrane of neuroglia, even in areas devoid of AChE-stained neuronal processes. GABA-T activity was present chiefly in dorsal horn neurones, and was absent from neuroglia.