OFF-responses of interneurons optimize avoidance behaviors depending on stimulus strength via electrical synapses
Fig 2
lin-32 is required for the determination of AIB interneurons, which are the key neurons for the optimization of probability of omega turn.
(A) A scheme of the first central layer interneurons in the primary and secondary circuits. ASH directly connects to AVA and AIB via chemical synapses. The fax-1 gene induces expression of nmr-1 in AVA. (B) fax-1 mutants show a partial avoidance defect to 2 M sorbitol, and lin-32 fax-1 double mutants show more reductions in omega turns and long reversals than the lin-32 and fax-1 single mutants. n = 20,19,20,21,20,17,15,17. (C) Wild type animal selectively expresses an electrical synapse gene, inx-1, in its AIB neurons (arrowhead), but a typical lin-32 mutant fails. fax-1 mutant normally expresses inx-1 (arrowhead). (D) The extrachromosomal expression of lin-32 cDNA driven by both its own promoter Plin-32 and AIB lineage-selective promoter Punc-130 fully rescues avoidance behaviors in response to 2 M sorbitol. n = 21,21,13,16. n = plate (cohort) of approximately 10–20 animals. The data are presented as the mean ± SEM.