The Relationship Between ChAT-immunoreactivity In The T Area Of Pre-piriform Cortex And Improves The Impairment Of Spatial Learning Memory In Intractable Epilepsy Rats By SVHRP

Background:Epilepsy is one of the neurodegenerative diseases, and 60%-70% temporal lobe epilepsy became the intractable epilepsy. Intractable epilepsy patients were customarily complicated by impairments in learning and memory because of recurrent attacks and side effect of long-term mediation , and intractable epilepsy animals were used to investigate the mechanism and chose the news drug .Objective:Our test uses intractable epilepsy rats as the model and explores the relationship between choline acetyl transferas (ChAT) - immunoreactivity in the pre-piriform cortex and improves the impairment of spatial learning memory of intractable epilepsy rats treated with the scorpion venom heart resistant protein (SVHRP ). Methods:SD rats(n=50) were injected with convulsive dose (10mg/kg.) of KA to make status epilepticus (SE) model. SE rats were randomly divided into treat group SE+NS and treat-administration group SE+SVHRP,which were respectively injected with SVHRP (0.25mg/kg)and simile equal volume physiological saline in the abdominal cavity for ten days. Meanwhile,another 30 rats which were injected with simile equal volume physiological saline with hypodermical injection were randomly divided into control group NS+NS and control-administration group NS+SVHRP, respectively injecting with SVHRP (0.25mg/kg)and simile equal volume physiological saline in the abdominal cavity for ten days. After 10 days,each group was injected with sub-threshold dose (5mg/kg s.c.) of KA. We detected the rat's spatial learning memory with Morris water maze. We assessed the change of ChAT - immunoreactivity in the pre-piriform cortex by immunohistochemistry.All data were expressed as mean±SEM. For all comparisons, values of p<0.05 were considered as statistically significant.Result:1,Ethology result:50 rats were injecting convulsive dose kainic acid (KA), showing prodrome such as gaze, wet dog shake ( WDS) in the 0-30 minutes; 1-5 degree epileptic attack in the 30-60minutes; 4-5 degree repteately spontaneous epileptic attack in 60-90 minutes; then status epilepticus,SE-epileptic attack endurance became longer and interval became shorter with bulk salivas and various kinds psychomotor symptoms. After 10 days injected sub-threshold dose (5mg/kg s.c.) of KA, 9 rats of SE+NS group behaved as defreee 4-5 seizure, among which 5 as degree5,4 as degree4,and2as degree 3; 4 rats of SE+SVHRP group behaved as defreee 4-5 seizure, among which 3 as degree5,4 as degree4, and 2as degree 3,3as degree2,4 as degree1,3 as degree0.No seizure was detected in NS+SVHRP and NS+NS group.Rank sunm test of ordered variables was used to test seizure degree and found that seizure degree in rats of SE+NS group were more than those in rats of NS+NS group.there was statistical significance between the 2 groups.It suggested that SE induced Intractable epilepsy rats could incrence epilepsy sensibility. Seizure degree in rats of SE+SVHRP group were less than those in rats of SE+NS group.there was statistical significance between the 2 groups.It sggested that SVHRP could reduce epilepsy sensibility.2,Morris water umaze result:As compared with the treat- administration group, control group and control-administration group, treat group showed that the search latency was much longer (P<0.01),and showed worse search strategy;the decreased number of platform crossings (P<0.01);the decreased percentage of total time and the distance in the trained quadrant(P<0.05).3,Immunohistochemistry result: Compared with the treat-admini- stration group,control group and control-administration group, there was asignificant decrease of the number of positive immune response acetylcholine ( Ach ) neurone of choline acetyl transferas (ChAT)with immune- ohistochemistry in the pre-piriform cortex, but the other three group had no different.Conclusion:1,SE induced Intractable epilepsy the piriform cortex of intractable epilepsy rats; rats showed increase in the susceptibility to the epilepsy stimulation. There was a significant decrease of the acetylcholine neurone in2,SVHRP have significant depressant effect on the epilepsy stimulat- eon;and have significant neuroprotective effect to protect neurone of the pre-piriform cortex from damage of intractable epilepsy rats;3,SVHRP can reduce the spatial learning memory deficits of intractable epilepsy rats,which maybe relate to reducing loss of neurons of the pre-piriform cortex and reducing sensitive to the epilepsy stimul- ation.But it is difficult to decide which is cause and effect.