title: Pyrazine analogues are active components of wolf urine that induce avoidance and freezing behaviours in mice.
abstract: BACKGROUND
  The common grey wolf (Canis lupus) is found throughout the entire Northern hemisphere and preys on many kinds of mammals. The urine of the wolf contains a number of volatile constituents that can potentially be used for predator-prey chemosignalling. Although wolf urine is put to practical use to keep rabbits, rodents, deer and so on at bay, we are unaware of any prior behavioural studies or chemical analyses regarding the fear-inducing impact of wolf urine on laboratory mice.
  
  
  RESULTS
  Three wolf urine samples harvested at different times were used in this study. All of them induced stereotypical fear-associated behaviors (i.e., avoidance and freezing) in female mice. The levels of certain urinary volatiles varied widely among the samples. To identify the volatiles that provoked avoidance and freezing, behavioural, chemical, and immunohistochemical analyses were performed. One of the urine samples (sample C) had higher levels of 2,6-dimethylpyrazine (DMP), trimethylpyrazine (TMP), and 3-ethyl-2,5-dimethyl pyrazine (EDMP) compared with the other two urine samples (samples A and B). In addition, sample C induced avoidance and freezing behaviours more effectively than samples A and B. Moreover, only sample C led to pronounced expression of Fos-immunoreactive cells in the accessory olfactory bulb (AOB) of female mice. Freezing behaviour and Fos immunoreactivity were markedly enhanced when the mice were confronted with a mixture of purified DMP, TMP, and EDMP vs. any one pyrazine alone.
  
  
  CONCLUSIONS
  The current results suggest that wolf urinary volatiles can engender aversive and fear-related responses in mice. Pyrazine analogues were identified as the predominant active components among these volatiles to induce avoidance and freezing behaviours via stimulation of the murine AOB.
authors: Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan. Erin.Gillam@ndsu.edu
authors: Kazumi
authors: K
authors: Osada
authors: Kenzo
authors: K
authors: Kurihara
authors: Hiroshi
authors: H
authors: Izumi
authors: Makoto
authors: M
authors: Kashiwayanagi
mesh_terms: D000818:Animals; D001362:Avoidance Learning; D001522:Behavior, Animal; D051379:Mice; D009812:Odorants; D009830:Olfactory Bulb / Q000187:drug effects / Q000378:metabolism; D010200:Panic; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D011719:Pyrazines / Q000737:chemistry / Q000494:pharmacology / Q000652:urine; D019596:Wolves / Q000652:urine
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D011719:Pyrazines
references: Proc Natl Acad Sci U S A. 1997 Mar 18;94(6):2210-4
references: 9122173
references: J Agric Food Chem. 2005 Aug 10;53(16):6443-7
references: 16076132
references: Behav Neurosci. 2007 Oct;121(5):1063-72
references: 17907837
references: Am Sci. 1975 Nov-Dec;63(6):628-37
references: 1200478
references: J Chem Ecol. 2007 Feb;33(2):417-34
references: 17191155
references: Behav Brain Res. 2009 Sep 14;202(2):218-24
references: 19463704
references: Chem Senses. 2008 Nov;33(9):815-23
references: 18653642
references: PLoS One. 2010 Jan 27;5(1):e8819
references: 20111698
references: Proc Natl Acad Sci U S A. 2010 Mar 16;107(11):5172-7
references: 20194746
references: Neurosci Biobehav Rev. 2005;29(8):1145-56
references: 16099043
references: PLoS One. 2008;3(10):e3591
references: 18974891
references: Diabetes. 1992 Oct;41 Suppl 2:42-8
references: 1526335
references: Proc Natl Acad Sci U S A. 1981 Sep;78(9):5817-20
references: 6946517
references: Proc Natl Acad Sci U S A. 2011 Jul 5;108(27):11235-40
references: 21690383
references: Cell. 2010 May 14;141(4):692-703
references: 20478258
references: Science. 1986 Feb 14;231(4739):722-5
references: 3945805
references: Life Sci. 1983 Feb 14;32(7):787-94
references: 6827911
references: J Exp Biol. 2009 Aug;212(Pt 15):2324-7
references: 19617424
references: Behav Neurosci. 2007 Feb;121(1):100-10
references: 17324054
references: Behav Neurosci. 2000 Oct;114(5):912-22
references: 11085605
references: Chem Senses. 2007 Mar;32(3):293-303
references: 17251176
references: J Chem Ecol. 2006 Dec;32(12):2617-27
references: 17131189
references: Horm Behav. 1990 Dec;24(4):497-509
references: 2286365
references: J Agric Food Chem. 2008 Mar 26;56(6):2147-53
references: 18318495
references: Neuroscience. 2008 Feb 19;151(4):937-47
references: 18201833
references: J Chem Ecol. 1985 Jul;11(7):921-35
references: 24310276
references: Nature. 1976 Oct 14;263(5578):587-8
references: 988483
references: J Chem Ecol. 1985 Jul;11(7):903-19
references: 24310275
references: Chem Senses. 2011 Jan;36(2):137-47
references: 20956737
references: Proc Biol Sci. 2003 May 7;270(1518):929-33
references: 12803907
references: Experientia. 1984 Jul 15;40(7):707-9
references: 6745399
references: Behav Processes. 2009 May;81(1):85-91
references: 19429201
references: J Nutr. 2007 Mar;137(3):589-93
references: 17311945
references: J Chem Ecol. 1986 Jan;12(1):277-96
references: 24306417
references: Neurosci Biobehav Rev. 2005;29(8):1157-67
references: 16095694
references: Neurosci Biobehav Rev. 2008 Sep;32(7):1259-66
references: 18579206
references: Chem Senses. 2011 Jun;36(5):443-52
references: 21398415
references: J Agric Food Chem. 2005 Aug 10;53(16):6531-6
references: 16076145
references: PLoS One. 2010 May 05;5(5):e10403
references: 20463952
references: Neurosci Biobehav Rev. 2008 Sep;32(7):1218-27
references: 18577397
references: Biochemistry. 1988 Mar 22;27(6):1901-7
references: 3132203
references: J Chem Ecol. 1994 Jul;20(7):1505-16
references: 24242647
references: Science. 1978 Feb 17;199(4330):796-8
references: 17836296
references: Curr Biol. 2004 Jan 20;14(2):R81-9
references: 14738757
references: Neuropsychopharmacology. 2002 Nov;27(5):744-55
references: 12431849
references: Nature. 2005 Mar 24;434(7032):470-7
references: 15724148
references: Experientia. 1987 Sep 15;43(9):998-1002
references: 3653342
references: J Chem Ecol. 1984 Jul;10(7):1007-18
references: 24318845
references: Br J Dermatol. 2008 Sep;159(4):780-91
references: 18637798