Worm Breeder's Gazette 10(3): 87

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Mutations that Cause Convulsions Against an Anesthetic, Ketamine

Hideki Ando and Hiroaki Kagawa

Figure 1

As a part of study on neuro-muscular function, we tried to isolate 
mutants having abnormal response against some anesthetics.  Sixteen 
strains of three independent mutations were isolated with EMS 
mutagenesis.  Those had specific response and convulsive movement in 
3OmM Ketamine-Hydrochloride(C13H16ClNO.HCl).  All mutants had similar 
response to another drugs; serotonine, octopamine, as N2.  In Ketamine,
N2 worm had two phased kinetics between time and paralytic states, 
but responded no obvious convulsion to ketamine.  Mutants basically 
show N2 like two phased kinetics, but were accompanied by clear 
convulsion during almost all stages.  Modes of these convulsion was 
classified into two classes; quick and vibration-like convulsions in 
15 strains.   But nine of those show twitcher in the absence of 
ketamine and other strains had similar as N2.  Another one shows wave-
like convulsive movement in 30mM ketamine and had cold-sensitive 
uncoordinated movement in the absence of ketamine.  This strain had 
almost paralytic phenotype at 16 C and recovered perfect motility 
after 40 min at 30 C.  
Genetic analysis shows that 16 strains divided into three 
independent mutations.  Three of nine strains having twitcher in the 
absence of ketamine were mapped on LG-IV and could not complement to 
unc-22(e66).  Strain J030 having wave-like convulsion was mapped on 
LGV.  Double mutant from trans configuration to dpy-11(e224) was not 
obtained.  This means that mutation site closed to dpy-11(e224), or 
might be the same cluster.  Other strains showing vibration-like 
convulsions in 30mM ketamine but normal behavior without ketamine was 
in progress.  One of them might be on LGII.  These results indicate 
that ketamine had multiple function to neuro-muscular mechanisms in 
the worm.  Further investigation of defectivity of these mutants and 
molecular characterization of defective genes allows us to know new 
aspects about mechanisms of receptor-effecter circuit and cold-
sensitive uncoordinated movement of C.  elegans.

Figure 1