Under physiological conditions y-aminobutyric acid (YAbu) poorly crosses the blood-brain barrier.'Of the putative yAbu mimetics prepared to date which enter the brain, only muscimol has been widely examined, and even this compound enters the brain to a very limited extent.* However, muscimol exhibits an unacceptable central nervous system toxicity, which prevents its wide clinical US^.^'^ From the pharmacological activities of muscimol and the ...
