| Objective:By studying the 5-HTR1A/cAMP/PKA pathway and related effect indicators,we observed the rehabilitation effect of abdominal massage on the hippocampus of young rats with hypoxic-ischemic brain injury,and explored the potential mechanism of abdominal massage in promoting the repair of hypoxic-ischemic brain injury.Methods:Five SPF grade pregnant mice gave birth to 40 healthy rat cubs.7-day-old rat cubs were randomly divided into two groups:the model group(n=28)and the sham operation group(n=12).The model group consisted of 28 cubs,and the Rice model method was used to establish a hypoxic ischemic brain injury rat model.The 24 successfully modeled rats were randomly divided into two groups:the model group(n=12)and the abdominal massage group(n=12).The abdominal massage group received pediatric abdominal massage techniques 24 hours after modeling,with continuous intervention for 28 days;The sham surgery group only separated the left common carotid artery without clipping,and no intervention measures were taken.The suspension test and balance beam test were carried out on the 7th,14th,21st and 28th day of intervention,and the 6-day water maze test was carried out on the 29th day after modeling;After the water maze test,the hippocampal tissue of the young rats in each group was taken,and the pathological morphological changes in the hippocampal CA1 area of the young rats were observed by HE staining at 400 times.The structural changes of hippocampal neurons were detected by transmission electron microscopy.The relative expression of 5-hydroxytryptamine 1 receptor(5-HTR1A)gene in the hippocampus was measured by RT-PCR,and the 5-hydroxytryptamine 1 receptor(5-HTR1A),cyclic adenosine phosphate(cAMP),protein kinase A(PKA),response element binding protein(CREB)The levels of synapsin 1(synl)and synapsin(syp)positive cells were measured,and the expression levels of cAMP,PKA,CREB,synl,and syp proteins in the hippocampus were measured using Western Blot method.Results:(1)The behavioral results showed that compared with the sham operation,the suspension test scores in the model group on the 21st and 28th days of intervention were significantly lower(P<0.05),and the balance beam test scores on the 14th,21st and 28th days were significantly higher(P<0.05).The number of times of water maze crossing the platform in the model group was significantly reduced(P<0.05),with statistically significant differences;Compared with the model group,the abdominal massage group significantly increased the suspension test score on the 21st and 28th day of intervention(P<0.05),significantly reduced the balance beam test score on the 21st and 28th days(P<0.05),and significantly increased the number of times of water maze crossing the platform in the abdominal massage group(P<0.05).(2)The HE staining results showed that the morphology and structure of hippocampal CA1 cells in the sham operated group were intact and neatly arranged;The cellular structure of the hippocampal CA1 region in the model group was disordered,with edema and necrosis of neuronal cells;The arrangement of cells in the CA1 area of the hippocampus in the abdominal massage group is clear,and the improvement of edema is significant.(3)The results of transmission electron microscopy showed that the nucleus and mitochondria of hippocampal neurons in the sham operated group were intact in structure and normal in morphology;The hippocampal neurons in the model group showed edema and degeneration,with an increase in perinuclear vacuoles;In the abdominal massage group,there was slight edema in the neuronal cells,with regular nuclear morphology and significant improvement in neuronal structure.(4)The RT-PCR results showed that compared with sham surgery,the relative expression of 5-HTR1A gene in the hippocampus of the model group was significantly reduced(P<0.05),and the differences were statistically significant;Compared with the model group,the relative expression of 5-HTR1A gene in the hippocampus of the abdominal massage group was significantly increased(P<0.05),and the differences were statistically significant.(5)The immunohistochemical results showed that compared with sham surgery,the number of positive cells for 5-HTR1A,cAMP,PKA,CREB,syn1,and syp in the hippocampus of the model group significantly decreased(P<0.05),and the differences were statistically significant;Compared with the model group,the number of positive cells for 5-HTR1A,cAMP,PKA,CREB,synl,and syp in the hippocampus of the abdominal massage group was significantly increased(P<0.05),and the differences were statistically significant.(6)The results of Western blot analysis showed that compared with sham surgery,the expression levels of cAMP,PKA,CREB,synl,and syp proteins in the hippocampus of the model group were significantly reduced(P<0.05),and the differences were statistically significant.Compared with the model group,the expression levels of cAMP,PKA,CREB,syn1,and syp proteins in the hippocampus of the abdominal massage group were significantly increased(P<0.05),and the differences were statistically significant.Conclusion:1.Abdominal massage can improve the balance movement,learning,memory and function of HIBD young rats.2.Abdominal massage can promote the recovery of damaged cell morphology and neuron structure in hippocampus.3.The effect of abdominal massage on promoting synaptic remodeling in HIBD young rats may be related to the expression of the 5-HTR1A/cAMP/PKA pathway. |
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