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Advanced Neurology Dysregulation of cAMP signaling pathway in MT2KO mice

A B

C D

Figure 1. Decreasing learning and memory in MT2KO and DKO mice. (A) The errors of jump from the platform after 2 – 4 h. **P < 0.01, compared with
C3H mice; P < 0.05 compared to MT2KO mice. (B) The latency time of jump from the platform after 24 h. **P < 0.01, compared with C3H mice; P < 0.05
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compared to MT2KO mice. (C) The errors of jump from the platform after 2 h. *P < 0.05, compared with C3H mice; P < 0.05 compared to MT2KO mice.
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(D) The latency time of jump from the platform after 24 h. *P < 0.05, compared with C3H mice; P < 0.05 compared to MT2KO mice.
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Abbreviations: MT2KO: Melatonin receptor 2 knockout; DKO: Double knockout.
A B C

D E F

Figure 2. Detection of the change of metabolites and hippocampus area by fMRI. (A) Relative quantification of Cho. *P < 0.05, compared with C3H mice.
(B) Relative quantification of mI. *P < 0.05, compared with C3H mice. (C) Relative quantification of NAA. (D) The relative volume of the hippocampus
from four groups. (E) Representative photomicrographs of Nissl staining from four groups. (F) The relative counts of neuron.
Abbreviations: fMRI: Functional magnetic resonance imaging; NAA: N-Acetyl-L-aspartic acid.

and found an increased plaque in MT2KO mice, instead of mice exhibited a decreased density of dendritic spines
MT1KO mice (Figure 3E and F). (Figure 4B) and percentage of matured spines (Figure 4C).
While the MT1KO mice exhibited normal dendritic
3.4. Abnormal dendritic spines and decreasing spine morphology (Figure 4A–C). Meanwhile, in the
synaptic proteins in MT2KO and DKO mice, instead purified crude synaptosomal fraction, we found that the
of MT1KO mice levels of NR2B, NR2A, glutamate receptor 1 (GluR1), and
Synapses were the basis of learning and memory. We GluR1-S845 in MT2KO and DKO mice were significantly
examined the structure of the synapses with Golgi staining reduced compared with control mice (Figure 4D and E).
(Figure 4A). We found that the MT2KO and the DKO However, there were no alterations in the level of multiple

Volume 2 Issue 3 (2023) 5 https://doi.org/10.36922/an.0974