Fig. (2).

Ultrastructure of neurons and synapses (n=3). In the sham operation group: (A, B) the neurons were intact, with homogeneous nuclei, abundant organelles, oval and full mitochondria, clear and intact double layer structure of the cristal membrane, endoplasmic reticulum attached with a large number of ribosomes (white arrows). (C) the synapses were normal with many synaptic vesicles secreted by presynaptic elements. The synaptic cleft was narrow, and the postsynaptic density was centralized (black arrows). In the model group: (D, E) neurons were not intact, with shrinking nuclei, severe loss of organelles, rarely normal mitochondria in vacuolar state, ruptured endoplasmic reticulum with obvious loss of ribose (white arrows). (F) the amount of synaptic vesicles secreted by presynaptic elements decreased. The synaptic cleft clearly widened, with sparse postsynaptic density (black arrows). In the OA group: (G, H) structures of neurons were intact on the whole, with homogeneous nuclei, abundant organelles, slightly swollen mitochondria, partial fusion and fracture of cristal membrane, slight loss of ribose of endoplasmic reticulum (white arrows). (I) abundant synaptic vesicles secreted by presynaptic elements could be observed. The synaptic cleft was clear, without obvious widening, and the postsynaptic density was centralized (black arrows).