1.Comparison of unilateral medial forebrain bundle and unilateral striatum lesioned by 6-hydroxydopamine at early lesioned stage in rat model
Wei Sun ; Chunming Wu ; Zhang Liu ; Namba Hiroki
Acta Universitatis Medicinalis Anhui 2023;58(4):554-560
Objective:
To compare the functional changes of neurotransmitters in the dopamine ( DA) system of rats lesioned by 6-hydroxydopamine in unilateral medial forebrain bundle ( MFB) and unilateral striatum after 4 weeks of modeling.
Methods :
Adult male Sprague-Dawley rats (n = 62) were divided randomly into four groups : single-site model ( one site striatal lesion model,n = 18) ,four-site model ( four sites striatal lesion model,n = 18) ,MFB model (MFB lesion model,n = 18) and a sham operated control group (n = 8) .Immunohistochemical tyrosine hydroxylase (TH) staining was used to calculate the loss rate of positive DA neurons.The functional changes of dopamine transporters(DAT) and D2 receptors in rat models of four groups were detected by radioligand-receptor binding assay in vitro,behavioral test and small-animal PET.
Results :
Immunohistochemical staining results of TH at 1-lesion,4-lesion and MFB model showed that the TH-positive cell loss rates of the lesion side in three models were 19. 1% ,84. 7% and 97. 1% ,respectively,indicating that the model was successfully constructed. The results of DAT / D2 receptor functions in the three models showed that,compared with the sham operated control group,the DAT binding ratio of radioactivity on the lesion side of 1-lesion,4-lesion and MFB model significantly decreased (P<0. 05,P<0. 05 and P<0. 01) .The DAT binding ratio of radioactivity on the lesion side was compared among 1,4 lesion and MFB model.It was found that the decrease degree of MFB model was significantly higher than that of the previous two models (P<0. 01) ,and the decrease degree of 4-lesion model was significantly higher than that of 1-lesion model (P<0. 05) .Compared with the sham operated control group,the D2 receptor binding ratio of radioactivity on the lesion side of 1-lesion and 4-lesion model significantly decreased (P<0. 05) , and there was no significant difference in the degree of decrease between the two models,but the D2 receptor binding ratio of radioactivity on the lesion side of MFB model significantly increased (P<0. 05) .There was no difference in the distribution of DAT / D2 receptor on the lesion side and the normal side of the sham operated control group.Methamphetamine caused ipsilateral rotations to the lesion side in all models. There were no significant differences in methamphetamine-induced rotation among 1-lesion,4-lesion and MFB models.Bromocriptine caused ipsilateral rotations to the lesion side in 1-lesion and 4-lesion models but contralateral rotations in MFB model. There were no significant differences in bromocriptine-induced rotation between 1-lesion and 4-lesion models.The results of stepping test showed the motion initiation time of the lesion side was significantly longer than that of the normal side,the stepping length of the lesion side was significantly shorter than that of the normal side,and the adjusting steps of the lesion side was significantly less than that of the normal side (P<0. 001) ,but there was no significant difference of the lesion side in the initiation time ,stepping length ,and adjusting steps among the three groups of models.
Conclusion
The striatal lesion and MFB lesion models showed different pathophysiological processes in terms of DA neurotransmitter functions and behavior.The MFB lesion model can mimic primary Parkinson's disease,while the striatal lesion model is similar to some Parkinson syndromes.
2.Cerebellar Hemorrhage due to a Direct Carotid–Cavernous Fistula after Surgery for Maxillary Cancer.
Yoshinobu KAMIO ; Hisaya HIRAMATSU ; Mika KAMIYA ; Shuhei YAMASHITA ; Hiroki NAMBA
Journal of Korean Neurosurgical Society 2017;60(1):89-93
Infratentorial cerebral hemorrhage due to a direct carotid–cavernous fistula (CCF) is very rare. To our knowledge, only four such cases have been reported. Cerebellar hemorrhage due to a direct CCF has not been reported. We describe a 63-year-old female who presented with reduced consciousness 3 days after undergoing a maxillectomy for maxillary cancer. Computed tomography showed a cerebellar hemorrhage. Magnetic resonance angiography showed a left-sided direct CCF draining into the left petrosal and cerebellar veins through the left superior petrosal sinus (SPS). Her previous surgery had sacrificed the pterygoid plexus and facial vein. Increased blood flow and reduced drainage could have led to increased venous pressure in infratentorial veins, including the petrosal and cerebellar veins. The cavernous sinus has several drainage routes, but the SPS is one of the most important routes for infratentorial venous drainage. Stenosis or absence of the posterior segment of the SPS can also result in increased pressure in the cerebellar and pontine veins. We emphasize that a direct CCF with cortical venous reflux should be precisely evaluated to determine the hemodynamic status and venous drainage from the cavernous sinus.
Cavernous Sinus
;
Cerebral Hemorrhage
;
Consciousness
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Constriction, Pathologic
;
Drainage
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Female
;
Fistula*
;
Hemodynamics
;
Hemorrhage*
;
Humans
;
Magnetic Resonance Angiography
;
Middle Aged
;
Veins
;
Venous Pressure


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