Expression And Significance Of GAP-43 In Lateral Geniculate Nucleus And Visual Cortex Area 17 Of Monocularly Deprived Rats

Objective: To investigate the expression of GAP-43 in the lateral geniculatenucleus and the visual cortex area 17 of monocularly deprived rats during the critical period, to understand the mechanism and seek out effective methods for preventing and treating deprived amblyopia during the development period. The study will offer a reference basis to prevent and treat amblyopia of deprivation among children.Methods: By suturing the eyelids of one eye of 14-day-old rats ,one monthlater,the lateral geniculate nucleus(LGN) and the visual cortex area 17 were sectioned in turn. These were investigated with polyclonal antibodies for GAP-43,which were used to label the neurons of visual system using the immunocytochemical SP method.Data were analyzed from optical microscopy and computer image analysis.Results: 1 The analysis revealed that GAP-43 immunopositive neurons in rats were localized in all the layers of lateral geniculate nucleus and the layers II -VI of visual cortex area 17,and GAP-43 is stained by a ring and dot figure and brown-yellow colour in cytomembrane ; 2, In the critical period, gene expression concentration and number of GAP-43 immunopositive neurons, in both the lateral geniculate nucleus and the visual cortex area 17, received from the deprived eyes, are reduced. ( P<0.05 )Conclusion: Expression level of GAP-43 in all the layers of lateral geniculatenucleus and the layers II -VI of visual cortex area 17 of monocularly deprived rats during the critical period are reduced. It is possible that the occurance of amblyopia is related to the reduction of the neurons abilities to express GAP-43 in visual system, and this decrease is in response to long-term deprivation .The results indicated that the role of GAP-43 in visual system is possibly one of the molecular biology basis of occurance of amblyopia.