The experimental study on an animal model of Alzheimer′s disease by intraventricular injection of the immunotoxin 192-IgG-saporin

ObjectiveTo establish an animal model of Alzheimer's disease in rats and to observe the alteration of learning and memory abilities of the animals and the changes of cholinergic neurons in the basal forebrain. Methods192-IgG-saporin (2.5 μg) was injected into the later ventricle of SD rats. After three weeks, learning and memory abilities were tested by Y-maze. After four weeks from the surgery, all the rats were sacrificed and the number of cholinergic neurons in the basal forebrain was counted through immunohistochemical method. ResultsY-maze test showed the abilities of learning and memory in the model groups (107.38±9.34, 3.75±0.71) were apparently decreased, in comparision with the normal groups, P0.01. Immunohistochemistry showed the number of cholinergic neurons in basal forebrain was decreased by 81.96%, 84.23% respectively in medial septum (MS) and vertical diagonal branch (VDB). Significant difference was found between the model groups and the normal groups (P0.01). The area and perimeter of neuron growth factor receptor (NGFR) positive neuron in MS/VDB of the model groups were significantly decreased (P0.05). The gray walue in MS/VDB of the model groups were strikingly advanced (P0.05). ConclusionThe intraventricular injection of the immunotoxin 192-IgG-saporin can simulate the alteration of the praxiology and pathological characteristics of AD partly.