Lhx6 delineates a pathway mediating innate reproductive behaviors from the amygdala to the hypothalamus.
In mammals, innate reproductive and defensive behaviors are mediated by anatomically segregated connections between the amygdala and hypothalamus. This anatomic segregation poses the problem of how the brain integrates activity in these circuits when faced with conflicting stimuli eliciting such mutually exclusive behaviors. Using genetically encoded and conventional axonal tracers, we have found that the transcription factor Lhx6 delineates the reproductive branch of this pathway. Other Lhx proteins mark neurons in amygdalar nuclei implicated in defense. We have traced parallel projections from the posterior medial amygdala, activated by reproductive or defensive olfactory stimuli, respectively, to a point of convergence in the ventromedial hypothalamus. The opposite neurotransmitter phenotypes of these convergent projections suggest a "gate control" mechanism for the inhibition of reproductive behaviors by threatening stimuli. Our data therefore identify a potential neural substrate for integrating the influences of conflicting behavioral cues and a transcription factor family that may contribute to the development of this substrate.
Choi
Gloria B
GB
Division of Biology 216-76, California Institute of Technology, Pasadena, California 91125, USA.
Dong
Hong-Wei
HW
Murphy
Andrew J
AJ
Valenzuela
David M
DM
Yancopoulos
George D
GD
Swanson
Larry W
LW
Anderson
David J
DJ
D000374:Aggression / Q000502:physiology; D000679:Amygdala / Q000166:cytology / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal; D002772:Cholera Toxin / Q000378:metabolism; D003220:Conflict, Psychological; D005260:Female; D005968:Glutamate Decarboxylase / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D007031:Hypothalamus / Q000166:cytology / Q000502:physiology*; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D007527:Isoenzymes / Q000378:metabolism; D060850:LIM-Homeodomain Proteins; D008297:Male; D026901:Membrane Transport Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016571:Neural Networks, Computer; D009434:Neural Pathways / Q000502:physiology*; D009812:Odorants; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013266:Stilbamidines / Q000493:pharmacokinetics; D013268:Stimulation, Chemical; D014157:Transcription Factors; D014556:Urine; D050599:Vesicular Glutamate Transport Protein 2
C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D018398:Homeodomain Proteins; D007527:Isoenzymes; C498504:LHX6 protein, mouse; D060850:LIM-Homeodomain Proteins; C102995:Lhx5 protein, mouse; C117058:Lhx9 protein, mouse; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D011506:Proteins; D016760:Proto-Oncogene Proteins c-fos; C493477:Slc17a6 protein, mouse; D013266:Stilbamidines; D014157:Transcription Factors; D050599:Vesicular Glutamate Transport Protein 2; C055324:phospholipase A2-activating protein; D049452:Green Fluorescent Proteins; D002772:Cholera Toxin; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1