1.The impact of amygdala glutamate receptors on cardiovascular function in rats with post-traumatic stress disorder.
Ya-Yang WU ; Kun-Yi CAI ; Yu-Jie WU ; Chao ZHENG ; Meng-Ya WANG ; Huan-Huan ZHANG
Acta Physiologica Sinica 2023;75(5):611-622
Post-traumatic stress disorder (PTSD) has been reported to be associated with a higher risk of cardiovascular disease. The amygdala may have an important role in regulating cardiovascular function. This study aims to explore the effect of amygdala glutamate receptors (GluRs) on cardiovascular activity in a rat model of PTSD. A compound stress method combining electrical stimulation and single prolonged stress was used to prepare the PTSD model, and the difference of weight gain before and after modeling and the elevated plus maze were used to assess the PTSD model. In addition, the distribution of retrogradely labeled neurons was observed using the FluoroGold (FG) retrograde tracking technique. Western blot was used to analyze the changes of amygdala GluRs content. To further investigate the effects, artificial cerebrospinal fluid (ACSF), non-selective GluR blocker kynurenic acid (KYN) and AMPA receptor blocker CNQX were microinjected into the central nucleus of the amygdala (CeA) in the PTSD rats, respectively. The changes in various indices following the injection were observed using in vivo multi-channel synchronous recording technology. The results indicated that, compared with the control group, the PTSD group exhibited significantly lower weight gain (P < 0.01) and significantly decreased ratio of open arm time (OT%) (P < 0.05). Retrograde labeling of neurons was observed in the CeA after microinjection of 0.5 µL FG in the rostral ventrolateral medulla (RVLM). The content of AMPA receptor in the PTSD group was lower than that in the control group (P < 0.05), while there was no significant differences in RVLM neuron firing frequency and heart rate (P > 0.05) following ACSF injection. However, increases in RVLM neuron firing frequency and heart rate were observed after the injection of KYN or CNQX into the CeA (P < 0.05) in the PTSD group. These findings suggest that AMPA receptors in the amygdala are engaged in the regulation of cardiovascular activity in PTSD rats, possibly by acting on inhibitory pathways.
Rats
;
Animals
;
Rats, Sprague-Dawley
;
Stress Disorders, Post-Traumatic
;
Receptors, AMPA
;
6-Cyano-7-nitroquinoxaline-2,3-dione/pharmacology*
;
Receptors, Glutamate/metabolism*
;
Amygdala
;
Weight Gain
;
Medulla Oblongata/physiology*
;
Blood Pressure
3.Expression changes of NaV channel subunits correlate with developmental maturation of electrophysiological characteristics of rat cerebellar Purkinje neurons.
Mingyu FU ; Xiaohong JI ; Lei ZHONG ; Qiong WU ; Haifu LI ; Ningqian WANG
Journal of Southern Medical University 2023;43(7):1102-1109
OBJECTIVE:
To investigate the variations in the expression of voltage-gated sodium (Nav) channel subunits during development of rat cerebellar Purkinje neurons and their correlation with maturation of electrophysiological characteristics of the neurons.
METHODS:
We observed the changes in the expression levels of NaV1.1, 1.2, 1.3 and 1.6 during the development of Purkinje neurons using immunohistochemistry in neonatal (5-7 days after birth), juvenile (12-14 days), adolescent (21-24 days), and adult (42-60 days) SD rats. Using whole-cell patch-clamp technique, we recorded the spontaneous electrical activity of the neurons in ex vivo brain slices of rats of different ages to analyze the changes of electrophysiological characteristics of these neurons during development.
RESULTS:
The expression of NaV subunits in rat cerebellar Purkinje neurons showed significant variations during development. NaV1.1 subunit was highly expressed throughout the developmental stages and increased progressively with age (P < 0.05). NaV1.2 expression was not detected in the neurons in any of the developmental stages (P > 0.05). The expression level of NaV1.3 decreased with development and became undetectable after adolescence (P < 0.05). NaV1.6 expression was not detected during infancy, but increased with further development (P < 0.05). NaV1.1 and NaV1.3 were mainly expressed in the early stages of development. With the maturation of the rats, NaV1.3 expression disappeared and NaV1.6 expression increased in the neurons. NaV1.1 and NaV1.6 were mainly expressed after adolescence. The total NaV protein level increased gradually with development (P < 0.05) and tended to stabilize after adolescence. The spontaneous frequency and excitability of the Purkinje neurons increased gradually with development and reached the mature levels in adolescence. The developmental expression of NaV subunits was positively correlated with discharge frequency (r=0.9942, P < 0.05) and negatively correlated with the excitatory threshold of the neurons (r=0.9891, P < 0.05).
CONCLUSION
The changes in the expression levels of NaV subunits are correlated with the maturation of high frequency electrophysiological properties of the neurons, suggesting thatmature NaV subunit expressions is the basis of maturation of electrophysiological characteristics of the neurons.
Rats
;
Animals
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Purkinje Cells/physiology*
;
Rats, Sprague-Dawley
;
Neurons
;
Brain
;
Sodium/metabolism*
4.Clinical and genetic analyses of Joubert syndrome in children.
Guang-Yu ZHANG ; Yun-Xia ZHAO ; Hui-Ling ZHAO ; Guo-Hao TANG ; Peng-Liang WANG ; Deng-Na ZHU
Chinese Journal of Contemporary Pediatrics 2023;25(5):497-501
OBJECTIVES:
To study the clinical and genetic features of Joubert syndrome (JS) in children.
METHODS:
A retrospective analysis was performed on the clinical data, genetic data, and follow-up data of 20 children who were diagnosed with JS in the Department of Children's Rehabilitation, the Third Affiliated Hospital of Zhengzhou University, from January 2017 to July 2022.
RESULTS:
Among the 20 children with JS, there were 11 boys and 9 girls. The common clinical manifestations were developmental delay (20 children, 100%), abnormal eye movement (19 children, 95%), and hypotonia (16 children, 80%), followed by abnormal respiratory rhythm in 5 children (25%) and unusual facies (including prominent forehead, low-set ears, and triangular mouth) in 3 children (15%), and no limb deformity was observed. All 20 children (100%) had the typical "molar tooth sign" and "midline cleft syndrome" on head images, and 6 children (30%) had abnormal eye examination results. Genetic testing was performed on 7 children and revealed 6 pathogenic genes, i.e., the CPLANE1, RPGRIP1L, MKS1, CC2D2A, CEP120, and AHI1 genes.
CONCLUSIONS
For children with developmental delay, especially those with abnormal eye movement and hypotonia, it is recommended to perform a head imaging examination to determine the presence or absence of "molar tooth sign" and "midline cleft syndrome", so as to screen for JS to avoid missed diagnosis and misdiagnosis. There are many pathogenic genes for JS, and whole-exome sequencing can assist in the diagnosis of JS.
Male
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Female
;
Humans
;
Child
;
Cerebellum
;
Abnormalities, Multiple/genetics*
;
Kidney Diseases, Cystic/genetics*
;
Eye Abnormalities/genetics*
;
Retina
;
Retrospective Studies
;
Muscle Hypotonia/genetics*
5.Magnetic resonance imaging features of cerebellar atrophy pattern after epilepsy.
Ximei FENG ; Qian WANG ; Hong JIN ; Shuai YANG ; Wu XING
Journal of Central South University(Medical Sciences) 2023;48(5):691-697
OBJECTIVES:
Clinically, it has been found that some patients with epilepsy are accompanied by cerebellar atrophy that is inconsistent with symptoms, but the pattern of cerebellar atrophy after epilepsy and the role of cerebellar atrophy in the mechanism of epilepsy have not been elucidated. This study aims to explore the specific pattern of cerebellar atrophy after epilepsy via analyzing magnetic resonance images in patients with postepileptic cerebellar atrophy.
METHODS:
A total of 41 patients with epilepsy, who received the treatment in Xiangya Hospital of Central South University from January 2017 to January 2022 and underwent cranial MRI examination, were selected as the case group. The results of cranial MRI examination of all patients showed cerebellar atrophy. In the same period, 41 cases of physical examination were selected as the control group. General clinical data and cranial MRI results of the 2 groups were collected. The maximum area and signal of dentate nucleus, the maximum width of the brachium pontis, the maximum anterior-posterior diameter of the pontine, and the maximum transverse area of the fourth ventricle were compared between the 2 groups. The indexes with difference were further subjected to logistic regression analysis to clarify the characteristic imaging changes in patients with cerebellar atrophy after epilepsy.
RESULTS:
Compared with the control group, the maximum width of the brachium pontis and the maximum anterior-posterior diameter of the pontine were decreased significantly, the maximum transverse area of the fourth ventricle was increased significantly in the case group (all P<0.05). The difference in distribution of the low, equal, and high signal in dentate nucleus between the 2 groups was statistically significant (χ2=43.114, P<0.001), and the difference in the maximum area of dentate nucleus between the 2 groups was not significant (P>0.05). The maximum width of the brachium pontis [odds ratio (OR)=3.327, 95% CI 1.454 to 7.615, P=0.004] and the maximum transverse area of the fourth ventricle (OR=0.987, 95% CI 0.979 to 0.995, P=0.002) were independent factors that distinguished cerebellar atrophy after epilepsy from the normal control, while the anterior-posterior diameter of pontine (OR=1.456, 95% CI 0.906 to 2.339, P>0.05) was not an independent factor that distinguished them.
CONCLUSIONS
In MRI imaging, cerebellar atrophy after epilepsy is manifested as significant atrophy of the brachium pontis, significant enlargement of the fourth ventricle, and increased dentate nucleus signaling while insignificant dentate nucleus atrophy. This particular pattern may be associated with seizures and exacerbated pathological processes.
Humans
;
Magnetic Resonance Imaging
;
Pons
;
Epilepsy/diagnostic imaging*
;
Atrophy/pathology*
;
Cerebellum/pathology*
7.Control of Emotion and Wakefulness by Neurotensinergic Neurons in the Parabrachial Nucleus.
Jingwen CHEN ; Noam GANNOT ; Xingyu LI ; Rongrong ZHU ; Chao ZHANG ; Peng LI
Neuroscience Bulletin 2023;39(4):589-601
The parabrachial nucleus (PBN) integrates interoceptive and exteroceptive information to control various behavioral and physiological processes including breathing, emotion, and sleep/wake regulation through the neural circuits that connect to the forebrain and the brainstem. However, the precise identity and function of distinct PBN subpopulations are still largely unknown. Here, we leveraged molecular characterization, retrograde tracing, optogenetics, chemogenetics, and electrocortical recording approaches to identify a small subpopulation of neurotensin-expressing neurons in the PBN that largely project to the emotional control regions in the forebrain, rather than the medulla. Their activation induces freezing and anxiety-like behaviors, which in turn result in tachypnea. In addition, optogenetic and chemogenetic manipulations of these neurons revealed their function in promoting wakefulness and maintaining sleep architecture. We propose that these neurons comprise a PBN subpopulation with specific gene expression, connectivity, and function, which play essential roles in behavioral and physiological regulation.
Parabrachial Nucleus/physiology*
;
Wakefulness/physiology*
;
Neurons/physiology*
;
Emotions
;
Sleep
8.Effects of RNA M6A demethylase ALKBH5 gene deficiency on morphology and function of cerebellum in aged mice.
Yi FEI ; Chun Hui MA ; Qing LI ; Wei SONG ; Wei Min TONG ; Ya Mei NIU
Chinese Journal of Pathology 2023;52(6):606-611
Objective: To investigate the effects of RNA m6A demethylase ALKBH5 gene deficiency on cerebellar morphology and function in the aged mice, and to explore the role of ALKBH5 in cerebellar degeneration. Methods: Western blot was performed to detect the protein level of ALKBH5 in the cerebellum of wild-type mice of various ages. The expression of NeuN, Calbindin-D28K, MAP2, GFAP and other proteins in the cerebella of middle-aged (12-month-old) and aged (18-month-old) wild-type mice and ALKBH5-/- mice was examined using immunohistochemistry. The balance beam test and gait analysis were performed to test the balance ability and motor coordination of the mice. Results: With aging of the mice, the expression of ALKBH5 in the cerebellum increased gradually in an age-dependent manner. In the aged mice, but not middle-aged mice, the body weight, whole brain weight and cerebellum weight of ALKBH5-/- mice decreased by 15%, 10% and 21%, respectively (P<0.05). The expression of ALKBH5 in the Purkinje cells was much higher than that in other types of neural cells. Correspondingly, ALKBH5-deficiency caused 40% reduction in the number of Purkinje cells, as well as the length and density of neuronal dendrites in the aged mice (P<0.01). In addition, the time for the aged ALKBH5-/- mice to pass the balance beam was 70% longer than that of the wild type mice of the same age, with unstable gaits (P<0.01). Conclusions: Gene deficiency of RNA m6A demethylase ALKBH5 causes cerebellar atrophy, Purkinje neuron loss and damage in the aged mice. These changes eventually affect mice's motor coordination and balance ability. These results suggest that imbalanced RNA m6A methylation may lead to neurodegenerative lesions in the cerebellum of mice.
Animals
;
Mice
;
AlkB Homolog 5, RNA Demethylase/metabolism*
;
Cerebellum/metabolism*
;
Methylation
;
RNA/metabolism*
9.Acute hypoxia blunts cold sensitivity through the inhibition of the lateral parabrachial nucleus in rats.
Ze-Jun WANG ; Tian YANG ; Qing-Yuan HUANG
Acta Physiologica Sinica 2023;75(3):351-359
To explore the changes of cold sensitivity after exposure to acute hypoxia and its mechanisms, Sprague-Dawley rats were divided into normoxia control group (21% O2, 25 °C), 10% O2 hypoxia group (10% O2, 25 °C), 7% O2 hypoxia group (7% O2, 25 °C), normoxia cold group (21% O2, 10 °C) and hypoxia cold group (7% O2, 10 °C). Cold foot withdrawal latency and preference temperature of each group were measured, skin temperatures were estimated using an infrared thermographic imaging camera, body core temperature was recorded by wireless telemetry system, immunohistochemical staining was used to detect the expression of c-Fos in the lateral parabrachial nucleus (LPB). The results showed that acute hypoxia significantly prolonged the latency of cold foot withdrawal and significantly enhanced the intensity of cold stimulation for foot withdrawal, and the rats under hypoxia preferred cold temperature. Cold exposure (10 °C) for 1 h significantly enhanced the expression of c-Fos in LPB of rats in normoxia, while hypoxia inhibited cold-induced c-Fos expression. Acute hypoxia significantly increased the skin temperature of feet and tails, decreased the skin temperature of interscapular region, and decreased the body core temperature of rats. These results indicate that acute hypoxia can significantly blunt cold sensitivity through the inhibition of LPB, suggesting actively keeping warm measures should be taken at the early stage after ascent to high altitude to prevent the upper respiratory infection and acute mountain sickness.
Rats
;
Animals
;
Rats, Sprague-Dawley
;
Parabrachial Nucleus/physiology*
;
Temperature
;
Cold Temperature
;
Hypoxia
;
Proto-Oncogene Proteins c-fos
10.Clinical features and genetic analysis of two Chinese pedigrees affected with Joubert syndrome.
Dengzhi ZHAO ; Yan CHU ; Ke YANG ; Xiaodong HUO ; Xingxing LEI ; Yanli YANG ; Chaoyang ZHANG ; Hai XIAO ; Shixiu LIAO
Chinese Journal of Medical Genetics 2023;40(1):21-25
OBJECTIVE:
To explore the clinical characteristics and genetic basis of two Chinese pedigrees affected with Joubert syndrome.
METHODS:
Clinical data of the two pedigrees was collected. Genomic DNA was extracted from peripheral blood samples and subjected to high-throughput sequencing. Candidate variants were verified by Sanger sequencing. Prenatal diagnosis was carried out for a high-risk fetus from pedigree 2.
RESULTS:
The proband of pedigree 1 was a fetus at 23+5 weeks gestation, for which both ultrasound and MRI showed "cerebellar vermis malformation" and "molar tooth sign". No apparent abnormality was noted in the fetus after elected abortion. The fetus was found to harbor c.812+3G>T and c.1828G>C compound heterozygous variants of the INPP5E gene, which have been associated with Joubert syndrome type 1. The proband from pedigree 2 had growth retardation, mental deficiency, peculiar facial features, low muscle tone and postaxial polydactyly of right foot. MRI also revealed "cerebellar dysplasia" and "molar tooth sign". The proband was found to harbor c.485C>G and c.1878+1G>A compound heterozygous variants of the ARMC9 gene, which have been associated with Joubert syndrome type 30. Prenatal diagnosis found that the fetus only carried the c.485C>G variant. A healthy infant was born, and no anomalies was found during the follow-up.
CONCLUSION
The compound heterozygous variants of the INPP5E and ARMC9 genes probably underlay the disease in the two pedigrees. Above finding has expanded the spectrum of pathogenic variants underlying Joubert syndrome and provided a basis for genetic counseling and prenatal diagnosis.
Female
;
Humans
;
Pregnancy
;
Pedigree
;
Cerebellum/abnormalities*
;
Abnormalities, Multiple/diagnosis*
;
Eye Abnormalities/diagnosis*
;
Kidney Diseases, Cystic/diagnosis*
;
Phosphoric Monoester Hydrolases/genetics*
;
Retina/abnormalities*
;
East Asian People
;
Mutation

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