ABSTRACT
Objective:
To explore the
role of hippocampal γ oscillation abnormality in
sepsis-associated encephalopathy (SAE).
Methods:
Seventy
male Sprague-Dawley rats (2-3 months) were randomly (random number) divided into three groups according to the random digital table
method:
sham, CLP, and CLP +
dopamine 4 (D4) receptor
agonists RO-10-5824 group. The SAE
animal model was established by cecal
ligation and
puncture (CLP). On day 10-14 after
surgery, the open field, novel object recognition, and
fear conditioning tests were performed. After that, the
hippocampus was collected to
measure expressions of
parvalbumin (PV) and D4 receptor. In another set of experiment, CA1 local field potential (LFP) were recorded, and the relationship between LFP and
time with novel object was analyzed. Independent sample t-test was used for pairwise comparisons, and multiple comparisons were performed by one-way
ANOVA, followed by the Tukey multiple comparisons test. Correlation was analyzed using Pearson correlation. Statistical significance was assumed when P<0.05.
Results:
Compared with the sham group, hippocampal PV (77.54±4.61)%, D4 expression (56.36±3.88)% and γ oscillation
power (41.1±8.62)%, object
exposure time (36±3) s, new object recognition rate (49±4)%, and scene stiffness
time (56±7) s were decreased significantly ( P<0.05). However, RO-10-5824
treatment could increase hippocaml γ oscillation
power (92.3±6.7)%, and reverse the decreased new object
exposure time (44±3) s and new object recognition rate (63±4)%. Correlation
analysis showed that hippocampal γ oscillation
power was positively associated with new object
exposure time ( r=0.609 2, P=0.015 9). There was no difference in total distance traveled or
time spent in the center among groups ( P>0.05).
Conclusion:
Hippocampal γ oscillation abnormality might
play a key
role in
cognitive impairment associated with SAE.