THE EMBRYO AND NARCOSIS, OR THE 

 SEPARATION OF FORM AND FUNCTION 



PURPOSE: To determine the efficiency of various depressants as emtryonic narcotics, and 

 to utilize such narcotics in an attempt to separate the development of form from func- 

 tion. 



MATERIALS : 



Biolopjlcal : Early Anuran or Urodele emhryos through stages of (muscular) motility, 

 (Anura stage #17, Urodela stage #27). 



Technical : Various known depressants: (None of these except freezing affect the 

 cilia) 



Acetanilid - l/l,000 (lethal at 1/200) Bapid recovery 



Alypin 



Anyl alcohol - 0.15^ 



Barhital sodium - l/lOO (lethal at l/l5) Slow recovery 



Borocaine 



Butyl alcohol - 0.5/^ 



Chloral hydrate - 0.1^ or I/5OO. Bapid recovery 



* Chloretone - 0.2 to 0.9^ or l/20,000 (lethal at 1/20OO) Bapid recovery 

 Chloroform - 0.05^ Bapid recovery 



CC^ gas 



Cocain 



Diethyl ether - l.U^ 



* Ethyl alcohol - k-.S^o or I/50 Bapid recovery 

 Ethyl chloride - 0.046 moles/liter 



* Ethyl urethane - 2.(yfi (Not suitable for prolonged exposure unless in 



weaker concentrations, i.e., 1.0^.) 

 Freezing 

 Methyl alcohol - 6.1|^ 



* MS 222 (M-Amino-Ethyl-Benzoate) - 1/5OOO. Can he autoclaved.** 

 Nembutal - 1/750 Slow recovery 



Novocaine 



Panthesine 



Paraldehyde - lAoO (lethal at l/lOO) 



Propyl alcohol - 1.5^ 



Stovaine 



Tutocain 



METHOD : 



Precautions : 



1. To function as an anesthetic, a drug must interfere with some physiological 

 process such as respiration or enzyme activity. The action of untested drugs 

 must not he prolonged beyond the stage of total anesthesia unless testing for its 

 persistent effect or lethality. 



2. All depressants are Immediately lethal in high concentrations. In very low con- 

 centrations, and repeated immersion, the embryo may become increasingly resistant 

 to narcosis. 



Controls : The controls consist of untreated embryos of the same age and stage, kept 

 under identical conditions except for the drug being tested on the experimentals. 



♦Suitable for these experiments. 

 ** Available through M. Sandoz 8e Co., 68 Charlton St., New York City. 



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