Objective To study the effect of high frequency stimulation (HFS) in pedunculopontine nucleus (PPN) on the neuronal activities of globus pallidus internus (Gpi) in Parkinson’s disease (PD) model rats, and the mechanisms there-of. Methods Seventy male Sprague-Dawley rats were divided into two groups, control group (n=30) and PD model group (n=40). PD rat model was established by the injection of 6-OHDA into substantia nigra pars compacta (SNc) on the right side of the brain with stereotactic technique. Electrophysiological recordings were made in anaesthetized rats to investigate the ef-fects of HFS-PPN on the firing rate of the GPi neurons. Brain microdialysis combined with high-performance liquid chroma-tography was applied to detect glutamate (Glu) andγ-aminobutyric acid (GABA) levels in GPi. Results HFS-PPN caused an excitatory reaction of the majority of neurons recorded in the GPi in PD model group and control group. The mean firing rate of GPi excited neurons was significantly increased (P﹤0.01). The levels of Glu were reduced under HFS-PPN and the levels of GABA were not affected (P>0.05).Conclusion HFS-PPN heightened the electrical activity of GPi neurons and re-duced the level of Glu. These excitatory effects were probably realized by PPN-GPi direct path or other indirect path.

AIM: To study the effects of astragalosides (AS) on the proliferation and cell cycle of rat glomerular mesangial cell (MC), and verify the correlation between the influence and the AS concentration. METHODS: The experiment was carried out in the Physiological Laboratory of Liaoning Medical University from December 2006 to July 2007. Rat glomerular MCs were cultured in high glucose for 4-7 passages. The experiments were randomly divided into control group and three AS groups with different concentrations (50, 100, 200 mg/L), which were treated with high-glucose liquid and AS respectively. MC proliferation was determined with MTT colorimetric method in each group at hours 48 after intervention. MC cell cycle was detected with flow cytometry. RESULTS: ①MTT results showed that, the values of A490 nm in AS groups were lower than that in the control group at hours 48 (P

Objective To explore the mechanism of the low-frequency electrical stimulate on pedunculopontine nu-cleus to treat the Parkinson (PD) through observinge the low-frequency electrical stimulation of Pedunculopontine Nucleus (PPN) in PD rat model and the effects of neurotransmitters (GPi) neurons discharge in the medial part of the globus pallidus. Methods Thirty SD rats were randomly assigned to the control group and the PD model group, with 15 in each group. PD model was established through injecting 6-OHDA into Substantia nigra compact (SNc) of black rat. Effect of low frequency electrical stimulation, micro-electrophoresis glutamate (Glu) and its receptor blocking breaking agent MK-801,γ-aminobu-tyric acid (GABA) and its receptor antagonist bicuculline (BIC) on discharge of rat neuron GPi was examined using extracel-lular unit recording methods through seven glass microelectrode recording. Results When stimulated by low frequency electrical stimulation of PPN, reactions from the control group and neuronal response GPi in PD rats were inhibited. The aver-age discharge frequency was reduced compared to pre-stimulation (P < 0.01). Micro-electrophoresis and BIC Glu excite neurons while microiontophoresis MK-801 and GABA restrain neurons. In the background of micro-electrophoresis BIC’s excitatory effects on neuron, low-frequency electrical stimulation on PPN reduced neuronal firing frequency. And in the background of inhibition effect of micro-electrophoresis MK-801, low-frequency stimulation PPN further restrain neuronal discharge frequency. Conclusion Low frequency electrical stimulation inhibits GPi PPN neuronal activity probably though regulating neurons projecting to the Glu and GABA nerve pathways in GPi neuron.

Objective:To assess the β-amyloid (Aβ) deposition of voxel-based PET imaging in Alzheimer′s disease (AD) and its relationships with blood biomarkers (Aβ).Methods:From January 2015 to December 2018, a total of 23 AD patients (9 males, 14 females, age (68.5±9.0) years; duration: (40.9±23.3) months; 8 mild patients, 15 moderate or severe patients) who underwent Aβ PET and with positive imaging results in Daping Hospital, Army Medical University were retrospectively enrolled. The information of Mini-Mental State Examination (MMSE) and Clinical Dementia Rating (CDR) were collected. Blood level of Aβ42, Aβ40 were measured. Differences of those metrics including Aβ42/Aβ40 between mild and moderate or severe patients were compared. For all 11C-Pittsburgh compound B (PIB) PET images, voxel-based one-sample independent t test analyses were performed. Voxel-based two-sample independent t test analyses were also performed between mild and moderate or severe patients. The voxel-based Pearson correlation analyses were run to assess the associations between blood metrics and Aβ deposition of 11C-PIB PET. Results:Comparing with mild patients, moderate or severe patients had lower MMSE (9.67±4.37 vs 17.13±2.80; t=4.349, P<0.001) and longer duration ((48.8±23.8) vs (26.0±13.5) months; t=-2.489, P<0.05). On voxel-wise analysis, amyloid PET illustrated brain Aβ deposition in bilateral frontal, right temporal, right occipital and posterior cingulate regions ( t values: 0.44-0.67, all P<0.001). Within AD, Aβ42/Aβ40 ( r values: from -0.62 to -0.41, 0.41-0.66, all P<0.05) were associated with amyloid PET, but not associated with Aβ42 ( r values: from -0.33 to 0, all P>0.05) or Aβ40 ( r values: from -0.41 to 0, all P>0.05). Conclusions:Based on voxel-wise analysis, 11C-PIB PET has comparable value for brain Aβ deposition. Aβ42/Aβ40 has the potential to predict brain Aβ deposition.

Objective:To investigate the diagnostic value of 11C-Pittsburgh compound B (PIB) in patients with mild cognitive impairment (MCI) and Alzheimer′s disease (AD) and explore the factors that may affect the binding of 11C-PIB. Methods:From January 2017 to December 2019, the 11C-PIB uptake of 6 patients with normal cognitive (NC; 3 males, 3 females, age: (64.5±12.3) years), 11 patients with MCI (4 males, 7 females, age: (64.5±9.8) years) and 21 patients with AD (7 males, 14 females, age: (68.1±9.1) years) from Daping Hospital, Army Medical University were retrospectively analyzed. Regional 11C-PIB binding was assessed by using standardized uptake value ratio (SUVR) and visual reading of 11C-PIB scan. Clinical data, including age, gender, education level, cognitive impairment, neuropsychological scale score, vascular risk factors (VRF), apolipoprotein E (ApoE) gene, were collected and differences among groups were analyzed by using one-way analysis of variance, least significant difference t test or Fisher exact test. Factors that affected the 11C-PIB binding were analyzed by multiple linear regression. Results:SUVR of cerebral lobe among NC, MCI and AD groups were significantly different (range of mean SUVR: 1.16-1.26, 1.19-1.35 and 1.40-1.61; F values: 5.331-9.279, all P<0.05). For positive PIB patients, SUVR of posterior cingulate and precuneus were increased in MCI group compared with NC group (1.20±0.15 vs 1.50±0.12, 1.18±0.15 vs 1.59±0.13; F values: 6.389 and 10.668, t values: -2.33 and -3.10, both P<0.05), and there were no significant differences in all lobes between MCI and AD group ( t values: from -1.29 to -0.51, all P>0.05). Visual analysis showed that the positive rates of PIB in frontal lobe (85.7%(18/21)), posterior cingulate (85.7%(18/21)), precuneus (81.0%(17/21)), temporal lobe (81.0%(17/21)) and occipital lobe (47.6%(10/21)) in AD were higher than those in MCI (4/11, 4/11, 4/11, 3/11 and 1/11, respectively; all P<0.05). Multiple linear regression showed that the degree of cognitive impairment were independent risk factors for SUVR of all lobes ( b values: 0.377-0.536, all P<0.05). The ApoE ε4 gene was independent risk factor for SUVR of precuneus ( b=0.290, P<0.05). Conclusion:11C-PIB is helpful for clinical diagnosis of MCI and AD patients and the degree of cognitive impairment and ApoE ε4 gene may be independent risk factors for increasing 11C-PIB binding.

Objective: To investigate the correlations among striatal dopamine transporter (DAT) distribution, glucose metabolism and Parkinson′s disease (PD) clinical symptoms. Methods: Twenty-five clinically confirmed idiopathic PD patients (17 males, 8 females, age: (59.8±9.2) years) who underwent ¹¹C-2-beta-carbomethoxy-3-beta-(4-fluorophenyl)tropane (CFT) and ¹⁸F-fluorodeoxyglucose (FDG) PET imaging from January 2015 to December 2016 were reviewed. The detailed clinical scores were systematically collected from all patients. Correlations between DAT distribution, glucose metabolism and clinical symptoms were evaluated at global and voxel levels using Pearson correlation analysis. Results: There were significantly positive correlations between the PD-related pattern (PDRP) value and unified PD rating scale (UPDRS) motor scores, non-motor symptoms scale (NMSS) scores, activity of daily living scale (ADL) scores (r values: 0.580, 0.522, 0.557, all P<0.05). The CFT uptake of ipsilateral caudate nucleus, anterior putamen, and posterior putamen were negatively correlated with UPDRS motor scores (r values: -0.496, -0.492, -0.457, all P<0.05), while those had no significant correlations with NMSS scores (r values: -0.420, -0.402, -0.355, all P>0.05). The CFT uptake of ipsilateral caudate nucleus and anterior putamen were negatively correlated with ADL scores (r values: -0.502, -0.522, both P<0.05). There were no significant correlations between CFT uptake in contralateral striatal, anterior putamen, posterior putamen and PDRP values, UPDRS motor scores, NMSS scores and ADL scores(r values: from -0.466 to -0.129, all P>0.05). The presence of the significant correlations between UPDRS motor scores, ADL scores and the CFT radioactive count were confirmed in left caudate nucleus and left putamen (r values: from -0.90 to -0.47, all P<0.05). The metabolic PET imaging disclosed a set of brain regions correlating with the clinical symptoms. The presence of significant correlations between the metabolic PET imaging and CFT uptake were confirmed in bilateral caudate nucleus (r values: 0.47-0.90, both P<0.01), precentral gyrus and insula (r values: -0.90 to -0.47, all P<0.01). Conclusion The correlations between DAT distribution, glucose metabolism and PD clinical symptoms are complicated, which promote the understanding in the proper application of dopaminergic and metabolic PET imaging in PD and offer more evidences in PD pathophysiological mechanisms.