| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 2800654 | General and Comparative Endocrinology | 2012 | 10 Pages |
The neurotransmitter serotonin (5-HT) may play a central role in the inhibition of socially regulated sex change in fish because of its known modulation of both aggressive and reproductive behavior. This is the first study to use immunohistochemical techniques to examine the morphometry of serotonergic neurons at different times during sex change. Using a model species wherein sex change is socially regulated via agonistic social interactions (the bluebanded goby, Lythrypnus dalli), we sampled brains of males and females with different social status, and of females at different times during sex change. Consistent with previous studies on other teleosts, immunoreactive neurons were found in the posterior periventricular nucleus (NPPv), the nucleus of the lateral recess (NRL), the nucleus of the posterior recess (NRP) and in the raphe nucleus. We measured the total area of NPPv, NRL, NRP, and the number and mean cell area of serotonergic neurons in the raphe nucleus. There was no significant difference in any of the brain regions between males, females or sex changing fish, but there was a slight increase in the number of dorsal raphe neurons in the brain of sex changers 2 h after male removal. The results show that in L. dalli the serotonergic system does not present any morphological sex and status differences, nor any dramatic modifications during sex change. These data, together with previous results, do not support the hypothesis that serotonin inhibits socially regulated sex change.
► We labeled neurons containing serotonin in the brain of the sex changing goby Lythrypnus dalli. ► We found immunoreactive neurons in two hypothalamic nuclei and in the raphe nucleus. ► In L. dalli the serotonergic system does not present any sex and status differences. ► The number and area of brain serotonergic neurons does not change during sex change. ► Our data do not support the hypothesis that serotonin inhibits protogynous sex change.
