Objective

2

To investigate the effect of

Tongdu Tiaoshen

acupunc

ture (for unblocking the obstruction in the governor vessel and reulating the spirit) on hippocampal neuronal synaptic remodeling in rats with post-stroke depression (PSD) based on the chemokine ligand 2-chemokine receptor 2 (CCL2-CCR2) pathway.

Methods

2

Fifty male SD rats were randomly selected from a total of 62 rats to establish PSD model via middle cerebral artery occlusion (MCAO) combined with chronic unpredictable mild stress (CUMS). Forty-eight successfully modeled rats were randomly divided into a model group

an acupuncture group

a fluoxetine group

and an acupuncture+agonist group

with 12 rats in each group. The remaining 12 normal rats were used as the blank group. The acupuncture group received

Tongdu Tiaoshen

acupuncture at "Dazhui" (GV14)

"Shuigou" (GV26)

"Shenting" (GV24)

and "Baihui" (GV20)

40 min per session

once daily

6 times per week. The fluoxetine group was administered with fluoxetine (5 mg/kg) by gavage once daily

7 times per week. The acupuncture+agonist group received acupuncture combined with intraperitoneal injection of recombinant CCL2 protein (1 μg)

once daily

7 times per week. Behavioral assessments included Longa neurological deficit score

sucrose preference test

and forced swimming test. ELISA was used to detect serum levels of inflammatory cytokines (tumor necrosis factor-α [TNF-α

]

interleukin-10 [IL-10

]

interleukin-6 [IL-6

]

). HE and Nissl staining were performed to observe hippocampal morphology. Transmission electron microscopy was used to observe the hippocampal synaptic ultrastructure. Western blot was used to detect the expression of CCL2-CCR2 pathway-related and neuronal synaptic remodeling-related proteins.

Results

2

Compared with the blank group

the model group exhibited severe damage to hippocampal structure

reduced neuronal number

decreased synapse count and postsynaptic density

increased Longa score

immobility time in the forced swimming test

TNF-α and IL-6 levels

and eleva

ted expression of CCL2 and CCR2 proteins (

P

<

0.05); while the sucrose preference index

IL-10 level

synaptic density (SD)

postsynaptic density thickness (PSDL)

and expression of synapsin 1 (SYN1)

synaptophysin (SYN)

and postsynaptic density proitein 95 (PSD95) proteins were significantly decreased (

P

<

0.05). Compared with the model group

both the acupuncture group and the fluoxetine group showed improved hippocampal structure

increased Nissl bodies

clearer neuronal nuclear membranes

increased synapse number and density

reduced Longa score

immobility time of swimming

TNF-αand IL-6 levels

and CCL2

CCR2 protein expression (

P

<

0.05)

and increased sucrose preference index

IL-10 level

SD

PSDL

and SYN1

SYN

PSD95 protein expression (

P

<

0.05). Compared with the acupuncture+agonist group

the acupuncture group showed better improvement in all indexes (

P

<

0.05).

Conclusion

2

Tongdu Tiaoshen

acupuncture could improve neurological function and depressive-like behavior in PSD rats

possibly by inhibiting the CCL2-CCR2 pathway and promoting neuronal synaptic remodeling in the hippocampus.