Abstract
Photoperiodic stimulation of quail (Coturnix coturnix japonica) resulted in the appearance of a nuclear fos-like protein within neurones of the basal tuberal hypothalamus. On transfer to long days the number of neurones containing this fos-like immunoreactivity increased from about 150 to 700, the neurones being scattered throughout the length of the tubero-infundibular complex. This activation had occurred by early in the second long day and was maintained for at least three long days. Over this period circulating levels of LH increased seven-fold, indicating that photoperiodic induction had taken place in the birds. A similar time-course of fos-like induction occurred in castrated quail exposed to a single long day and then returned to short days. Activation mirrored the long-term changes in LH secretion found in this paradigm and fos-like immunoreactivity showed the same "carry-over" characteristics of photoperiodic induction, being maximal two days after the quail had been exposed to the single long day (and were again on short days) and when LH secretion was at its maximum. Activation of fos-like immunoreactive cells did not take place when long-day quail were transferred to short photoperiods. The evidence supports the view that the neurones being activated are involved in a specific fashion in the avian photoperiodic response.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.