Effects of special brain area regional cerebral blood flow abnormal perfusion on learning and memory function and its molecular mechanism in rats

To study the effect of special brain area regional cerebral blood flow (rCBF) abnormal perfusion on learning and memory function and its molecular mechanism, 64 adult male healthy Sprague-Dawley (SD) rats were randomly divided into two groups, the false operation group (control group) and the operation group (model group). After surgical operation, the operation group undertook bilateral common carotid artery permanent ligation, while the other group did not. Learning and memory function were measured by Y-maze at 4 h, 8 h, 24 h and 3 d after surgical operation, respectively. The rCBF of the right frontal lobe and hippocampus was also detected by the PerifluxPF model laser Doppler flowmetry, and the expressions of c-fos or c-jun or Bcl-2 and Bax were also measured by immune histochemistry S-P method accordingly. Results showed that the rCBF of the right frontal lobe and hippocampus in the operation group was significantly lower than that in the false operation group (P < 0.05). The learning indexes, error number (EN), day of reach standard and total reaction time (TRT) in the operation group, were significantly higher than that in the false operation group (P < 0.05). However, the initiative evasion rate in the operation group was significantly lower than that in the false operation group. The study also found that the rCBF was relatively more, the indexes (EN, the day of reach standard and TRT) relatively fewer, but the initiative evasion rate and the memory keeping rate were relatively more. The positive expression and the average absorbency of Fos and Jun in the operation group were significantly higher than that in the false operation group (P < 0.05). Furthermore, Bax and Bcl-2 positive cells were all increased over time in the operation group, and the expression ratio of Bax/Bcl-2 in the operation group was significantly higher than that in the false operation group (P < 0.01). In conclusion, rCBF decrease can impair the learning and memory function in rats, which may be related to the increase of the expression ratio of c-fos or c-jun or Bcl-2 or Bax in the frontal cortex and hippocampus.