2.Spatial Distribution of Parvalbumin-Positive Fibers in the Mouse Brain and Their Alterations in Mouse Models of Temporal Lobe Epilepsy and Parkinson's Disease.
Changgeng SONG ; Yan ZHAO ; Jiajia ZHANG ; Ziyi DONG ; Xin KANG ; Yuqi PAN ; Jinle DU ; Yiting GAO ; Haifeng ZHANG ; Ye XI ; Hui DING ; Fang KUANG ; Wenting WANG ; Ceng LUO ; Zhengping ZHANG ; Qinpeng ZHAO ; Jiazhou YANG ; Wen JIANG ; Shengxi WU ; Fang GAO
Neuroscience Bulletin 2023;39(11):1683-1702
Parvalbumin interneurons belong to the major types of GABAergic interneurons. Although the distribution and pathological alterations of parvalbumin interneuron somata have been widely studied, the distribution and vulnerability of the neurites and fibers extending from parvalbumin interneurons have not been detailly interrogated. Through the Cre recombinase-reporter system, we visualized parvalbumin-positive fibers and thoroughly investigated their spatial distribution in the mouse brain. We found that parvalbumin fibers are widely distributed in the brain with specific morphological characteristics in different regions, among which the cortex and thalamus exhibited the most intense parvalbumin signals. In regions such as the striatum and optic tract, even long-range thick parvalbumin projections were detected. Furthermore, in mouse models of temporal lobe epilepsy and Parkinson's disease, parvalbumin fibers suffered both massive and subtle morphological alterations. Our study provides an overview of parvalbumin fibers in the brain and emphasizes the potential pathological implications of parvalbumin fiber alterations.
Mice
;
Animals
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Epilepsy, Temporal Lobe/pathology*
;
Parvalbumins/metabolism*
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Parkinson Disease/pathology*
;
Neurons/metabolism*
;
Interneurons/physiology*
;
Disease Models, Animal
;
Brain/pathology*
3.Number changes and axonal sprouting of neuropeptide Y interneurons in the hippocampus of pilocarpine-induced rats.
Zhiguo WU ; Lili LONG ; Bo XIAO ; Si CHEN ; Fang YI
Journal of Central South University(Medical Sciences) 2009;34(2):93-98
OBJECTIVE:
To investigate the role of neuropeptide Y(NPY) positive interneurons in the generation and compensation of temporal lobe epilepsy.
METHODS:
Pilocarpine-induced rat model was founded. Immunohistochemistry was used to observe the number changes and axonal sprouting of NPY interneurons at different time points in the hippocampus of rats.
RESULTS:
After lithium-chloride and pilocarpine administration, 92.9% rats were induced status epilepticus (SE) successfully, and the mortality rate was 19.2%. In the experimental group, the number of NPY positive neurons decreased in the hilus of the hippocampus, and was least on 7 d after the SE (P<0.01). In the chronic phase, the number of hilus NPY neurons partially recovered, but was still less than the number in the control group on 60 d after the SE (P<0.05). No evident changes of the number of NPY neurons existed in CA domains (P>0.05) except the loss of them in CA3 area on 7 d after the SE (P>0.05). Increased NPY positive fibers could be seen in the molecular layer of the dentate gyrus on 30 d after the SE.
CONCLUSION
NPY interneurons have different sensitivities to the injuries induced by seizures at different time points and domains. Loss of NPY interneurons plays an important role in the generation of temporal lobe epilepsy, while axonal sprouting of them may play a significant role in the compensation of temporal lobe epilepsy.
Animals
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Epilepsy, Temporal Lobe
;
chemically induced
;
pathology
;
Hippocampus
;
metabolism
;
pathology
;
Interneurons
;
metabolism
;
pathology
;
Male
;
Neuropeptide Y
;
metabolism
;
Pilocarpine
;
Random Allocation
;
Rats
;
Rats, Sprague-Dawley
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Retrograde Degeneration
;
pathology
;
Status Epilepticus
;
chemically induced
;
pathology
4.Research on distribution and expression of NMDA receptors and parvalbumin-positive neurons in intractable epilepsy-related focal cortical dysplasia.
Lei LIU ; Yue-Shan PIAO ; Wei WANG ; Li CHEN ; Li-Feng WEI ; Hong YANG ; De-Hong LU
Chinese Journal of Pathology 2008;37(1):16-20
OBJECTIVETo evaluate the alteration of subunits composition in NMDA receptor and the alterations of the expression and distribution of NMDA receptors and parvalbumin (PV)-positive neurons in focal cortical dysplasia (FCD) cortices.
METHODSTwenty cases of FCD samples (including all four subtypes of FCD) obtained during epilepsy surgery and 4 controls were analysed by immunohistochemical staining for NR1, NR2A/B and PV.
RESULTSIncreased expression of NR1 was detected in the giant neurons and dysmorphic neurons in FCD; while pronounced expression of NR2A/B was detected in immature neurons, giant neurons and dysmorphic neurons of FCD, especially in somata and processes of the immature neurons. Compared with the controls, FCD cortices showed prominent scattered arrangement of PV positive neurons and fibers, dramatically decreased number of PV positive interneurons and PV background staining, especially in foci of FCD II subtype.
CONCLUSIONThere are increased expressions of NR1 and NR2A/B subunits in FCD abnormal neurons, as well as scattered and reduced expressions of PV positive neurons and fibers in FCD cortices.
Adolescent ; Biomarkers, Tumor ; metabolism ; Cerebral Cortex ; metabolism ; pathology ; Child ; Child, Preschool ; Epilepsies, Partial ; pathology ; Female ; Gene Expression Regulation ; Humans ; Infant ; Interneurons ; metabolism ; Male ; Malformations of Cortical Development ; pathology ; Neurons ; metabolism ; Parvalbumins ; analysis ; isolation & purification ; Receptors, N-Methyl-D-Aspartate ; genetics ; metabolism
5.Axonal sprouting of somatostatin positive interneurons in the hippocampus in epileptic rats.
Fang YI ; Bo XIAO ; Ting JIANG ; Lili LONG ; Jinghui LIANG ; Li FENG ; Guoliang LI
Journal of Central South University(Medical Sciences) 2011;36(12):1176-1182
OBJECTIVE:
To investigate the axonal sprouting of somatostatin(SS) positive interneurons in temporal lobe epilepsy.
METHODS:
6-8 week-old healthy male SD rats were divided randomly into an epileptic group (treated by lithium and pilocarpine intraperitoneal injection) and a control group (by lithium and normal sodium intraperitoneal injection). Each group was randomly divided into 5 subgroups at 1,7,15,30, amd 60 d after the injection. Immunohistochemistry method was used to detect the number changes of SS or neuronal nuclei (NeuN) positive neurons in different domains of the hippocampus at different time points in each group, and the coexpression of SS positive interneurons combined with NeuN was detected by double immunofluorescence to observe the dynamic changes and axonal sprouting of SS positive interneurons.
RESULTS:
The number of SS neurons in the experimental group exceeded that in the control group in the CA1 area at 60 d post-status epileptieus SE (P<0.01), and numerous SS positive fibers were seen throughout the layers of the CAl area at 60 d post-SE. NeuN positive neurons in the stratum oriens and stratum radiatum layers in the initiation site of the CA1 area were beyond normal at 60 d post-SE. The number of double labeled SS interneurons gradually rose at 15 d in stratum oriens of CA1, and even exceeded that of the controls in the stratum oriens and stratum radiatum layers of CA1 at 60 d.
CONCLUSION
The numerous SS positive fibers throughout the layers of the CAl area at 60 d post-SE come from the increased interneurons in the stratum oriens and stratum radiatum layers of CA1 area. The pathological axonal sprouting may play an important role in the generation and compensation of temporal lobe epilepsy.
Animals
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Axons
;
metabolism
;
pathology
;
CA1 Region, Hippocampal
;
cytology
;
metabolism
;
physiopathology
;
Efferent Pathways
;
pathology
;
physiology
;
Epilepsy, Temporal Lobe
;
chemically induced
;
metabolism
;
physiopathology
;
Interneurons
;
cytology
;
metabolism
;
pathology
;
Male
;
Pilocarpine
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Random Allocation
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Rats
;
Rats, Sprague-Dawley
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Somatostatin
;
metabolism
;
Temporal Lobe
;
metabolism
6.Laminar Distribution of Neurochemically-Identified Interneurons and Cellular Co-expression of Molecular Markers in Epileptic Human Cortex.
Qiyu ZHU ; Wei KE ; Quansheng HE ; Xiongfei WANG ; Rui ZHENG ; Tianfu LI ; Guoming LUAN ; Yue-Sheng LONG ; Wei-Ping LIAO ; Yousheng SHU
Neuroscience Bulletin 2018;34(6):992-1006
Inhibitory GABAergic interneurons are fundamental elements of cortical circuits and play critical roles in shaping network activity. Dysfunction of interneurons can lead to various brain disorders, including epilepsy, schizophrenia, and anxiety. Based on the electrophysiological properties, cell morphology, and molecular identity, interneurons could be classified into various subgroups. In this study, we investigated the density and laminar distribution of different interneuron types and the co-expression of molecular markers in epileptic human cortex. We found that parvalbumin (PV) and somatostatin (SST) neurons were distributed in all cortical layers except layer I, while tyrosine hydroxylase (TH) and neuropeptide Y (NPY) were abundant in the deep layers and white matter. Cholecystokinin (CCK) neurons showed a high density in layers IV and VI. Neurons with these markers constituted ~7.2% (PV), 2.6% (SST), 0.5% (TH), 0.5% (NPY), and 4.4% (CCK) of the gray-matter neuron population. Double- and triple-labeling revealed that NPY neurons were also SST-immunoreactive (97.7%), and TH neurons were more likely to express SST (34.2%) than PV (14.6%). A subpopulation of CCK neurons (28.0%) also expressed PV, but none contained SST. Together, these results revealed the density and distribution patterns of different interneuron populations and the overlap between molecular markers in epileptic human cortex.
Adolescent
;
Adult
;
Brain Chemistry
;
genetics
;
physiology
;
Cerebral Cortex
;
metabolism
;
pathology
;
Child
;
Cholecystokinin
;
metabolism
;
Epilepsy
;
etiology
;
pathology
;
Female
;
Gene Expression Regulation
;
physiology
;
Humans
;
Interneurons
;
metabolism
;
Male
;
Middle Aged
;
Neuropeptide Y
;
metabolism
;
Parvalbumins
;
metabolism
;
Phosphopyruvate Hydratase
;
metabolism
;
Somatostatin
;
metabolism
;
Tyrosine 3-Monooxygenase
;
metabolism
;
Young Adult