Protocols for total RNA extraction, complementary DNA (cDNA) synthesis and
quantitative real-time polymerase chain reaction (PCR) were described previously.18 (link) Tissues of the hippocampus were extracted for total RNA with a Trizol kit
(Invitrogen, Carlsbad, CA, USA). According to M-mlv reverse transcription kit
(Takara, Shiga, Japan) instructions, total RNA was synthesized to cDNA.
Real-time PCR was performed with FastStart Universal SYBR Green Master (Rox)
(Roche, Switzerland) and monitored with a real-time PCR system (Applied
Biosystems 7500 Real-Time PCR Systems). The primer sequences are summarized in
Table 1. The
relative expression levels of each primer sequence messenger RNA (mRNA) were
analysed by the 2−ΔΔCt algorithm, normalized to glyceraldehyde 3-phosphate
dehydrogenase (GAPDH) and relative to the control groups.