2.4. Sample preparations
The brain (supraesophageal ganglion), the five thoracic ganglia
(combined), the six abdominal ganglia (combined), and the ovaries
were collected at mid-day from ten animals at each ovarian stage
(as defined by Meeratana and Sobhon, 2007). Each organ was carefully
dissected, and its wet mass was weighed. Samples were
placed in 50 ll 0.1 M perchloric acid. The mixture was then sonicated
and centrifuged at 14,000g at 4 C. The supernatants were
then collected and filtered through a 0.22 lmSpin-x centrifugal filter
tube before injection onto the HPLC column. Detection and
quantification of 5-HT and DA in the CNS and ovaries were performed
by using High Performance Liquid Chromatography with