The Research On Cognitive Functionin Heat Stroke Rats

Objective By the Whole Genome Oligo Microarray of rat and the Morris water maze in heat stroke rats,to dicuss the changes of cognitive function after going through heat stroke and possible mechanism of cognitive impaiment.Methods Supervising the heat stroke rats’ mean arterial pressure and core temperature and observing the changes of cognitive function by the Morris water maze on the 7th day after the heat stroke.Then, Screening of differentially expressed genes in hippocampus of heat stroke rats using rats whole genomic oligonucleotide microarrays.Results 1,Severe pulmonary edema was found in most of the rats when the core temperature reached to 42℃. We builded 44 heat stroke model rats,which died on 16 and the survival rate of 53.6%.The learning and memory ability of the heat stroke rats decreased after the heat stroke.2, There are 188 differentially expressed genes was statistically significant by using rat whole genomic oligonucleotide microarrays,and 99 up-regulated genes and 89 downregulated genes were found comparing with control rats. Among them, 7up-regulated genes(Jun,Hspa1 a,Hspa1b,Hspa11,Hspb1,I11 b,Ddit3)were related to MAPK signal pathways. PDE9 A protein that is coded by the downregulated Pde9 a gene is a high affinity for specific phosphodiesterase,and can regulate the central nervous system diseases by stoping selectively the hydrolysis of c AMP and c GMP which involve in learning and memory barriers. CXCL12 protein,also knowed as stromal cell derived fator(SDF-1), that is coded by the downregulated Cxcl12 gene play an important role in the nerve cells’ migration,neurotransmitter release and theregulation of hippocampus cell synaptic plasticity.Furthermore,the lower expression Sema4 f gene code Sema4 F protein is a member of Semaphorin family.Sema4 F play a vital function in neurons axon guidance,regulation of axon branch and hippocampal neurons synaptic contact and maintenance of synapticity plasticitu.At the same time,Slit2 protein is encoded by the lower expression Slit2 gene is also a member of axon guidance factor family proteins as semaphorins,and regulat the generation of axons,the synaptic connection between axon and synaptic plasticity and reconstruction.In addition,CSPG4 protein is encoded by the lower expression Cspg4 gene is an important component in the cental nervous system’ extracellular martrix(ECM).It play an important role in the development of the central nervous and maintain the nervous system’ normal function after the mature.Then,heme oxygenase1(HO-1) is encoded by the up-regulated Hmox1 genes is the initial enzyme of heme degration.It plays am important role in protecting cell by participating anti-oxidation,anti-inflammatory and anti appotosis pcocess.Conclusions 1, The learning and memory ability in rats decreased after heat stroke.2,The rats brain damaged widely and seriously after heat stroke,and MAPK signal pathway may be involved in the process of heat stroke on brain damage.3, The lower expression of Pde9 a gene,Cxcl12 gene,Cxcl12gene,Slit2 gene,Cspg4gene,et al may play an important role in the process of learning and memory impaiment after heat stroke.