EEG Characteristics in Frequency Domain in Synaptic Dysfunction Rat Model / 现代生物医学进展

ABSTRACT

EEG characteristics in frequency domain were investigated in the frontal lobe, occipital lobe and hippocampus, i.e. cognition - related cortex of synaptic dysfunction model rat, providing electrophysiological basis for further study on plastic extent and nerve regeneration of the damaged neurons. Synaptic dysfunction model was made via microinjecting β - amyloid protein1 - 40 (Aβ1 - 40) into hippocampal CA1 area of rat. Morris water maze behavioral test was performed to evaluate the learning and memory function of model group. Then EEG in the above areas for two groups were recorded. The spectrum for two groups was performed and the characteristics in frequency domain were analyzed. The results showed (1) The average escape latency in 3rd, 4th, 5th and 6th training times of model group are higher than those of normal. The average escape latency of normal group in 5th training time decreased more markedly than that in 2nd training time, while that of model group in 7th training time decreased more remarkably than that in 2nd training time (P ＜0.05). Without platform, the platform quadrant time percentage of model group was lower than the control (P ＜0.05). (2) Alpha rhythm in EEG of model rat was slowing down; alpha- band power decreased with peek frequency left shifted nearly 2Hz. And the power of delta - band and theta - band in frontal lobe, occipital and hippocampus all increased with different extent. The synaptic dysfunction model rats were made successfully by microinjecting Aβ1 - 40 method. The model rats show the decreased learning and memory dysfunction. EEG frequency spectrum features in model rat show slower alpha rhythm with power amplitude lower or loss, slow waves (delta and theta wave) increasing with higher power amplitude. These can be consistent with the EEG of Alzheimer's disease patients, which can provide electrophysiological basis for further plasticity and nerve regeneration study on the impaired cortex with synaptic dysfunction.