ABSTRACT
Progressive accumulation of the amyloid-β peptide (Aβ) in the brain plays a central role in the pathogenesis of Alzheimer's disease (AD). The animal model of intracerebral injection of Aβ oligomers not only provides a method for further exploring the mechanism of Aβ in AD, but also can be used to screen drug candidates targeting Aβ oligomers. This animal model has been widely used in the study of anti-AD drugs and mechanism of AD. In this paper, we summarize the research progress in the animal model of intracerebral injection of soluble Aβ oligomers, including experimental animals, the types of Aβ, the preparation of Aβ oligomers in vitro, injection sites and doses, the duration of modeling, animal behavioral changes, and the pathological mechanisms relating to this animal model, which will contribute to the application of the animal model to various conditions.
ABSTRACT
A 34-year-old man who previously underwent a craniotomy due to oligodendroglioma was admitted with a diagnosis of recurrent brain tumor. An awake craniotomy was planned. Approximately 15 minutes after completing the scalp nerve block, his upper torso suddenly moved and trembled for 10 seconds, suggesting a generalized clonic seizure. He recovered gradually and fully in 55 minutes without any neurological sequelae. The emergency computed tomography scan revealed a localized fluid collection and small intracerebral hemorrhage nearby in the temporoparietal cortex beneath the skull defect. He underwent surgery under general anesthesia at 8 hours after the seizure and was discharged from the hospital after 10 days. This report documents the first case of generalized seizure that was caused by the accidental intracerebral injection of local anesthetics. Although the patient recovered completely, the clinical implications regarding the scalp infiltration technique in a patient with skull defects are discussed.
Subject(s)
Adult , Humans , Anesthesia, General , Anesthetics, Local , Brain Neoplasms , Cerebral Hemorrhage , Craniotomy , Diagnosis , Emergencies , Nerve Block , Oligodendroglioma , Scalp , Seizures , Skull , TorsoABSTRACT
OBJECTIVE: To observe the effect of electroacupuncture (EA) and EA combined with intracerebral injection of vascular endothelial growth factor (VEGF) on endoplasmic reticulum stress (ERS) related proteins and genes as activating transcription factor (ATF 6), inositol requiring enzyme-1 (IRE 1), CCAAT/enhancer binding protein homologous protein (CHOP), X box-binding protein-1 (XBP 1) of cerebral ischemia reperfusion injury (CIRI) rats, so as to study its repair effect for CIRI. METHODS: Forty male SD rats were equally and randomly divided into 5 groups: sham operation, model, EA, VEGF and EA+VEGF groups (n=8). The CIRI model was established by occlusion of the middle cerebral artery (MCAO) with thread embolism method. For rats of the sham operation group, the right common carotid artery was isolated without MCAO. EA (2 Hz/100 Hz, 1-3 mA) was applied to "Baihui" (GV 20), left "Quchi" (LI 11) and left "Zusanli" (ST 36) for 30 min, once a day for 14 days. For rats of the VEGF and EA+VEGF groups, 10 µL VEGF (0.025 µg/µL) was injected into the lateral ventricle 24 h after successful modeling. The rats' neurological function was assessed by using the modified neurological severity score (mNSS), and the histopathological changes of cerebral tissue were observed by Nissl staining method. The expression levels of ERS related proteins and genes ATF 6, IRE 1, XBP 1 and CHOP were determined by western blot (WB) and fluorescent quantitative PCR, separately. RESULTS: After modeling, the level of mNSS was significantly higher in the model group than in the sham operation group (P<0.05), and the number of Nissl bodies was markedly lower in the model group than in the sham operation group (P<0.05). Following the treatment, the mNSS was significantly lower in the EA, VEGF and EA+VEGF groups than in the model group (P<0.05), and the numbers of Nissl bodies were obviously higher in the EA, VEGF and EA+VEGF groups than in the model group (P<0.05), suggesting an improvement of neurological dysfunction and a repair of the injured cerebral tissue after the treatment. The levels of CIRI-induced increase of mNSS and CIRI-induced decrease of the number of Nissl bodies in the EA+VEGF group were respectively remarkably lower or higher than those of the simple EA and simple VEGF groups (P<0.05). WB and PCR showed that the expression levels of ATF 6, IRE 1, XBP1 and CHOP proteins and genes were notably higher in the model group than in the sham operation group (P<0.05), and considerably lower in the EA, VEGF and EA+VEGF groups than in the model group (P<0.05). Comparison among the three treatment groups showed that after the treatment, the expression levels of ATF 6, IRE 1, XBP1 and CHOP proteins and genes were obviously lower in the EA+VEGF group than in the EA and VEGF groups (P<0.05). CONCLUSION: EA and EA plus intracerebral microinjection of VEGF can improve neurological function and promote cerebral tissue repair in CIRI rats, which is associated with their effects in down-regulating the expression of ERS related proteins ATF 6, IRE 1, XBP1 and CHOP. The effect of EA+VEGF is superior to that of simple EA and simple VEGF.
ABSTRACT
Objective To establish the model for periventricular leukomalacia(PVL) by intracerebral injection of 3-nitropropionic acid (3-NPA) and explore realistic model for concerned studies and investigate the diagnostic method with magnetic resonance imaging (MRI) examination. MethodsSprague-Dawley rat pups of both sexes at the age of postnatal day 5 (P5) were randomized and divided into two groups: NPA group and PBS group , and they were injected the same volume of 3-NPA and PBS with a tip located at the corpus callosum above the left ventricle by stereotaxis instrument, respectively. One day (P6), two days (P7), three days (P8) and nine days (P14) after injection, the injections were transcardially perfused and brains were collected. Then sections of brains were undertaken HE staining; growth and the time of opening eyes of the rats in the two different groups were observed and compared. Neurobehaviorai activity and memory tests were performed on postnatal day 29 (P29) and day 30 (P30). MRI examination was performed on postnatal day 30 (P30). ResultsMore weight increase and slower opening eye time were found in the NPA group compared with PBS group (P < 0.05). In the NPA group, sub-cortical and periventricular white matter rarefaction were observed by HE staining on P6, P7 and P8, significant lateral ventricle enlargement was found on P14, while the same changes were not found in the PBS group, and no histological changes in gray matter were noted in both groups. The outcomes of neurobehavioral tests of NPA group were much more abnormal compared with the PBS group (P < 0.05). MRI examination disclosed the signal changes of brain tissue is worse in the NPA group than that of the PBS group in muscle strength of limbs, autocinesis, capability and white matter. ConclusionsThe model for PVL induced by intracerebral injection of 3-NPA is characterized by damage to the periventricular white matter. The model can stimulate the pathologic change factually in vivo. The neurobehavioral movement is consistent with.clinical symptom. It can be used as a model to investigate some related disease. MRI examination is a feasible diagnostic method to show anatomic changes of white matter injury of the brain.