Autapses selectively form in specific cell types in many brain regions.Previous studies have also found putative autapses in principal spiny projection neurons(SPNs)in the striatum.However,it remains unclear whether t...Autapses selectively form in specific cell types in many brain regions.Previous studies have also found putative autapses in principal spiny projection neurons(SPNs)in the striatum.However,it remains unclear whether these neurons indeed form physiologically functional autapses.We applied whole-cell recording in striatal slices and identified autaptic cells by the occurrence of prolonged asynchronous release(AR)of neurotransmitters after bursts of high-frequency action potentials(APs).Surprisingly,we found no autaptic AR in SPNs,even in the presence of Sr^(2+).However,robust autaptic AR was recorded in parvalbumin(PV)-expressing neurons.The autaptic responses were mediated by GABA_(A) receptors and their strength was dependent on AP frequency and number.Further computer simulations suggest that autapses regulate spiking activity in PV cells by providing self-inhibition and thus shape network oscillations.Together,our results indicate that PV neurons,but not SPNs,form functional autapses,which may play important roles in striatal functions.展开更多
Tibetan singing bowls emit low-frequency sounds and produce perceptible harmonic tones and vibrations through manual tapping.The sounds the singing bowls produce have been shown to enhance relaxation and reduce anxiet...Tibetan singing bowls emit low-frequency sounds and produce perceptible harmonic tones and vibrations through manual tapping.The sounds the singing bowls produce have been shown to enhance relaxation and reduce anxiety.However,the underlying mechanism remains unclear.In this study,we used chronic restraint stress or sleep deprivation to establish mouse models of anxiety that exhibit anxiety-like behaviors.We then supplied treatment with singing bowls in a bottomless cage placed on the top of a cushion.We found that unlike in humans,the combination of harmonic tones and vibrations did not improve anxietylike behaviors in mice,while individual vibration components did.Additionally,the vibration of singing bowls increased the level of N-methyl-D-aspartate receptor 1 in the somatosensory cortex and prefrontal cortex of the mice,decreased the level ofγ-aminobutyric acid A(GABA)receptorα1 subtype,reduced the level of CaMKII in the prefrontal cortex,and increased the number of GABAergic interneurons.At the same time,electrophysiological tests showed that the vibration of singing bowls significantly reduced the abnormal low-frequency gamma oscillation peak frequency in the medial prefrontal cortex caused by stress restraint pressure and sleep deprivation.Results from this study indicate that the vibration of singing bowls can alleviate anxiety-like behaviors by reducing abnormal molecular and electrophysiological events in somatosensory and medial prefrontal cortex.展开更多
Traumatic brain injury can cause loss of neuronal tissue, remote symptomatic epilepsy, and cognitive deficits. However, the mechanisms underlying the effects of traumatic brain injury are not yet clear. Hippocampal ex...Traumatic brain injury can cause loss of neuronal tissue, remote symptomatic epilepsy, and cognitive deficits. However, the mechanisms underlying the effects of traumatic brain injury are not yet clear. Hippocampal excitability is strongly correlated with cognitive dysfunction and remote symptomatic epilepsy. In this study, we examined the relationship between traumatic brain injury-induced neuronal loss and subsequent hippocampal regional excitability. We used hydraulic percussion to generate a rat model of traumatic brain injury. At 7 days after injury, the mean modified neurological severity score was 9.5, suggesting that the neurological function of the rats was remarkably impaired. Electrophysiology and immunocytochemical staining revealed increases in the slope of excitatory postsynaptic potentials and long-term depression（indicating weakened long-term inhibition）, and the numbers of cholecystokinin and parvalbumin immunoreactive cells were clearly reduced in the rat hippocampal dentate gyrus. These results indicate that interneuronal loss and changes in excitability occurred in the hippocampal dentate gyrus. Thus, traumatic brain injury-induced loss of interneurons appears to be associated with reduced long-term depression in the hippocampal dentate gyrus.展开更多
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,...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 coexpression 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), and4.4%(CCK) of the gray-matter neuron population. Doubleand 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.展开更多
基金supported by the National Natural Science Foundation of China(32130044,31630029,32171094,and 32100930)the National Key Research and Development Program of China(2021ZD0202500).
文摘Autapses selectively form in specific cell types in many brain regions.Previous studies have also found putative autapses in principal spiny projection neurons(SPNs)in the striatum.However,it remains unclear whether these neurons indeed form physiologically functional autapses.We applied whole-cell recording in striatal slices and identified autaptic cells by the occurrence of prolonged asynchronous release(AR)of neurotransmitters after bursts of high-frequency action potentials(APs).Surprisingly,we found no autaptic AR in SPNs,even in the presence of Sr^(2+).However,robust autaptic AR was recorded in parvalbumin(PV)-expressing neurons.The autaptic responses were mediated by GABA_(A) receptors and their strength was dependent on AP frequency and number.Further computer simulations suggest that autapses regulate spiking activity in PV cells by providing self-inhibition and thus shape network oscillations.Together,our results indicate that PV neurons,but not SPNs,form functional autapses,which may play important roles in striatal functions.
基金supported by the National Natural Science Foundation of ChinaNos.32170950(to LY),31970915(to LY),31871170(to CL)+4 种基金the Natural Science Foundation of Guangdong Province for Major Cultivation ProjectNo.2018B030336001(to LY)the Natural Science Foundation of Guangdong Province,Nos.2021A1515010804(to CL),2023A1515010899(to CL)the Guangdong Grant‘Key Technologies for Treatment of Brain Disorders’No.2018B030332001(to CL)。
文摘Tibetan singing bowls emit low-frequency sounds and produce perceptible harmonic tones and vibrations through manual tapping.The sounds the singing bowls produce have been shown to enhance relaxation and reduce anxiety.However,the underlying mechanism remains unclear.In this study,we used chronic restraint stress or sleep deprivation to establish mouse models of anxiety that exhibit anxiety-like behaviors.We then supplied treatment with singing bowls in a bottomless cage placed on the top of a cushion.We found that unlike in humans,the combination of harmonic tones and vibrations did not improve anxietylike behaviors in mice,while individual vibration components did.Additionally,the vibration of singing bowls increased the level of N-methyl-D-aspartate receptor 1 in the somatosensory cortex and prefrontal cortex of the mice,decreased the level ofγ-aminobutyric acid A(GABA)receptorα1 subtype,reduced the level of CaMKII in the prefrontal cortex,and increased the number of GABAergic interneurons.At the same time,electrophysiological tests showed that the vibration of singing bowls significantly reduced the abnormal low-frequency gamma oscillation peak frequency in the medial prefrontal cortex caused by stress restraint pressure and sleep deprivation.Results from this study indicate that the vibration of singing bowls can alleviate anxiety-like behaviors by reducing abnormal molecular and electrophysiological events in somatosensory and medial prefrontal cortex.
基金supported by the National Natural Science Foundation of China,No.81330029,81501057the Natural Science Foundation of Tianjin of China,No.17JCQNJC12000the Tianjin Medical University General Hospital Funding in China,No.ZYYFY2016014
文摘Traumatic brain injury can cause loss of neuronal tissue, remote symptomatic epilepsy, and cognitive deficits. However, the mechanisms underlying the effects of traumatic brain injury are not yet clear. Hippocampal excitability is strongly correlated with cognitive dysfunction and remote symptomatic epilepsy. In this study, we examined the relationship between traumatic brain injury-induced neuronal loss and subsequent hippocampal regional excitability. We used hydraulic percussion to generate a rat model of traumatic brain injury. At 7 days after injury, the mean modified neurological severity score was 9.5, suggesting that the neurological function of the rats was remarkably impaired. Electrophysiology and immunocytochemical staining revealed increases in the slope of excitatory postsynaptic potentials and long-term depression（indicating weakened long-term inhibition）, and the numbers of cholecystokinin and parvalbumin immunoreactive cells were clearly reduced in the rat hippocampal dentate gyrus. These results indicate that interneuronal loss and changes in excitability occurred in the hippocampal dentate gyrus. Thus, traumatic brain injury-induced loss of interneurons appears to be associated with reduced long-term depression in the hippocampal dentate gyrus.
基金supported by the National Natural Science Foundation of China (31430038 and 81571275)
文摘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 coexpression 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), and4.4%(CCK) of the gray-matter neuron population. Doubleand 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.
