. 2021 Mar 9;217(3):iyab004. doi: 10.1093/genetics/iyab004

Table 1.

A nonexhaustive list of compounds that attract or repel wild-type animals in the laboratory and the neurons demonstrated to detect them

Chemical stimulus	Neuron(s)	Soluble (S) or Volatile (V)	Reference(s)
Attractants
Cyclic nucleotides cAMP cGMP	ASE (ADF, ASG, ASI)	S	(Ward 1973) (Bargmann and Horvitz 1991)
Cations Na⁺ K⁺	ASEL (ADF, ASG, ASI) ASER (ASEL)	S	(Ward 1973) (Dusenbery 1974) (Bargmann and Horvitz 1991) (Pierce-Shimomura et al. 2001) (Ortiz et al. 2009)
Anions Cl⁻	ASER (ADF, ASG, ASI)	S	(Ward 1973) (Dusenbery 1974) (Bargmann and Horvitz 1991) (Pierce-Shimomura et al. 2001)
Basic pH	ASEL	S	(Ward 1973) (Dusenbery 1974) (Murayama et al. 2013)
Amino acids Lysine Histidine Cysteine Methionine	ASE (ASG, ASI, ASK)	S	(Ward 1973) (Bargmann and Horvitz 1991) (Ortiz et al. 2009)
Biotin	ASE (ADF, ASG, ASI)	S	(Bargmann and Horvitz 1991)
Pyrazine	AWA	V	(Bargmann et al. 1993)
Diacetyl (low)	AWA	V	(Bargmann et al. 1993)
Diacetyl (intermediate)^a	AWA, AWC	V	(Chou et al. 2001)
2,4,5-Trimethylthiazole (low)	AWA, AWC	V	(Bargmann et al. 1993)
Butyric acid^b	AWA (AWC ?)	V	(Choi et al. 2018)
Isobutyric acid	AWA (AWC ?)	V	(Choi et al. 2018)
Benzyl proprionate	AWA, AWC	V	(Choi et al. 2018)
Benzaldehyde (low)	AWC (AWA)	V	(Bargmann et al. 1993) (Leinwand et al. 2015)
Isoamyl alcohol (low)	AWC (AWA)	V	(Bargmann et al. 1993)
2-Butanone	AWC^ON	V	(Bargmann et al. 1993) (Wes and Bargmann 2001)
Acetone	AWC^ON	V	(Bargmann et al. 1993) (Worthy et al. 2018)
Dimethylthiazole	AWC	V	(Bargmann et al. 1993) (Choi et al. 2018)
1-Methylpyrrole	AWC	V	(Choi et al. 2018)
1-Pentanol	AWC	V	(Bargmann et al. 1993) (Choi et al. 2018)
2-Cyclohexylethanol	AWC	V	(Choi et al. 2018)
2-Ethoxythiazole	AWC	V	(Bargmann et al. 1993) (Choi et al. 2018)
2-Isobutylthiazole	AWC (AWA ?)	V	(Bargmann et al. 1993) (Choi et al. 2018)
2-Methylpyrazine	AWC (AWA ?)	V	(Choi et al. 2018)
4-Chlorobenzyl mercaptan	AWC (AWA ?)	V	(Choi et al. 2018)
Benzyl mercaptan	AWC (AWA ?)	V	(Choi et al. 2018)
2-Heptanone	AWC^ON	V	(Bargmann et al. 1993) (Zhang et al. 2016)
2,3-Pentanedione (low)	AWC^OFF	V	(Chou et al. 2001) (Wes and Bargmann 2001)
2,3-Pentanedione (intermediate) ^c	AWA, AWC	V	(Chou et al. 2001)
Repellents (avoidance)
Acidic pH	ASH, ADF, ASK, ASE	S	(Dusenbery 1974) (Sambongi et al. 2000)
Basic pH (>10.5)	ASH	S	(Sassa et al. 2013)
Copper	ASH, ADL, ASE	S	(Bargmann et al. 1990)^c (Sambongi et al. 1999)
Cadmium	ASH, ADL, ASE	S	(Sambongi et al. 1999)
SDS	ASH (ASK, ASI, ASJ) PHA, PHB (antagonistic)	S	(Bargmann et al. 1990)^c (Hilliard et al. 2002) (Liu et al. 2018)
Bitters quinine	ASH (ASK)	S	(Hilliard et al. 2004)
Diacetyl (high)	ASH	V	(Yoshida et al. 2012) (Taniguchi et al. 2014)
2,4,5-Trimethylthiazole (high)		V	(Bargmann et al. 1993) (Yoshida et al. 2012)
Benzaldehyde (high)	ASH (AWB)	V	(Bargmann et al. 1993) (Troemel et al. 1995) (Luo et al. 2008) (Yoshida et al. 2012)
Isoamyl alcohol (high)	ASH (ADL, AWB)	V	(Luo et al. 2008) (Yoshida et al. 2012)
Alcohols 1-Octanol (100%) 1-Octanol (30%)	ASH (ADL, AWB—off food) ASH	V	(Bargmann et al. 1993) (Troemel et al. 1995) (Troemel et al. 1997) (Chao et al. 2004)
Ketones 2-Nonanone	AWB (ASH)	V	(Bargmann et al. 1993) (Troemel et al. 1997) (Tanimoto et al. 2017)
Serrawettin W2	AWB	S	(Pradel et al. 2007)
Phenazine-1-carboxamide	ASJ	S	(Meisel et al. 2014)
Pyochelin	ASJ	S	(Meisel et al. 2014)
Dodecanoic acid	ASH (ADL ?, ADF ?) PHA PHB	S	(Tran et al. 2017)

The references include those first reporting behavioral response to the chemicals, as well as those demonstrating the neurons involved in the response. The roles of most neurons were shown by cell ablation, although some were revealed via genetic mutation or calcium imaging. Neurons with a more minor role are indicated by a smaller font. Question marks indicate neurons with a possible role in detecting a stimulus.

Chou et al. (2001) refers to 1:10 dilutions of diacetyl and 2,3-pentanedione as “high” concentration. We have indicated them here as “intermediate” to distinguish it from undiluted diacetyl and 2,3-pentanedione, which animals avoid (Yoshida et al. 2012).

Butyric acid was previously reported to be a neutral compound (Bargmann et al. 1993).

J. Thomas unpublished, cited in Bargmann et al. (1990).