Objective: To study the correlation of deprivation effect of acupuncture against amblyopia and brain derived neurotrophic factor for revealing its relative mechanism.Methods: Eighteen young cats(4 weeks old) were averagely randomized into normal control

model and acupuncture groups.Amblyopia model was established by suturing unilateral eyelids.One day after operation

for rats of acupuncture group

"Jingming"(BL 1)

"Chengqi"(ST 1)

"Qiuhou"(EX-HN 7)

and "Cuanzhu"(BL 2) were punctured

once daily

16 weeks altogether.At the end of experiments

the cats were killed for taking tissues of visual cortical Area 17

lateral geniculate body and retina.These tissues were then embedded with Epon812 epoxy resin and cut into sections and stained with immunohistochemical technique.Ultrastructural changes of the neurons were observed with transmission electronic microscope and the integral optical density(IOD) values

numerical density(ND) of immuno-reaction positive cells were detected.Results: Marked retrograde degeneration of visual cortical neurons(irregular shape of the nuclear membrane

shrinkage and vacuolar degeneration of mitochondria

derangement of mitochondrial crista

irregularity of synaptic vesicles

enlargement of synaptic gaps

etc) was found in model group

while that in acupuncture group lightened at different degrees. In comparison with normal control group

the values of ND and IOD of brain derived neurotrophic factor(BDNF) in visual cortex

lateral geniculate body and retinal ganglion cells were obviously lowered

while those values of ND and IOD of acupuncture group were significantly higher than those of model group(P<0.01);no significant differences were found between normal control and acupuncture groups in these two indexes.It indicated that acupuncture could inhibit unilateral eyelid suture induced neuronal retrograde degeneration of the visual cortex and down-regulation of BDNF expression in amblyopia cats.Conclusion: Acupuncture can prevent visual deprivation induced ultrastructural injury of the visual cortical neurons

which may be partially related to upregulation of BDNF expression.