RRC ID 49506
Author Ansai S, Hosokawa H, Maegawa S, Naruse K, Washio Y, Sato K, Kinoshita M.
Title Deficiency of Serotonin in Raphe Neurons and Altered Behavioral Responses in Tryptophan Hydroxylase 2-Knockout Medaka (Oryzias latipes).
Journal Zebrafish
Abstract Serotonin (5-hydroxytryptamine [5-HT]) is a bioactive monoamine that acts as a neurotransmitter in the central and peripheral nervous system of animals. Teleost fish species have serotonergic neurons in the raphe nuclei of the brainstem; however, the role of 5-HT in the raphe neurons in teleost fish remains largely unknown. Here, we established a medaka (Oryzias latipes) strain with targeted disruption of tryptophan hydroxylase 2 (tph2) gene that is involved in the 5-HT synthesis in the raphe nuclei. Immunohistochemistry and mass spectrometry analysis revealed that the homozygous mutants (tph2Δ13/Δ13) lacked the ability to synthesize 5-HT in the raphe neurons. To investigate the effects of 5-HT deficiency in adult behaviors, the mutant fish were subjected to five behavioral paradigms (diving, open-field, light-dark transition, mirror-biting, and two-fish social interaction). The homozygous mutation caused a longer duration of freezing response in all examined paradigms and reduced the number of entries to the top area in the diving test. In addition, the mutants exhibited a decreased number of mirror-biting in the males and an increased contact time in direct social interaction between the females. These results indicate that this tph2-knockout medaka serves as a good model to analyze the effects of 5-HT deficiency in the raphe neurons.
Volume 14(6)
Pages 495-507
Published 2017-12
DOI 10.1089/zeb.2017.1452
PII 10.1089/zeb.2017.1452
PMID 28933662
MeSH Animals Animals, Genetically Modified / genetics* Animals, Genetically Modified / growth & development Animals, Genetically Modified / metabolism Behavior, Animal Female Male Neurons / metabolism* Oryzias / genetics* Oryzias / growth & development Oryzias / metabolism Raphe Nuclei / metabolism* Serotonin / deficiency* Tryptophan Hydroxylase / physiology*
IF 1.742
Times Cited 5
Medaka d-rR/TOKYO (MT837) tph2^ex6delta13 (MT1074)