Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inh...Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. Moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased complexity and restructuring of neural network structures, as well as the addition of new granule granule cells that aid in olfactory adaptation. Additionally, the manuscript underscores the importance of employing precise methodologies to elucidate the specific roles of adult neurogenesis amidst conflicting data and varying experimental paradigms. Understanding these processes is essential for gaining insights into the complexities of olfactory function and behavior.展开更多
Iron is the most abundant transition metal in the brain and is essential for brain development and neuronal function;however,its abnormal accumulation is also implicated in various neurological disorders.The olfactory...Iron is the most abundant transition metal in the brain and is essential for brain development and neuronal function;however,its abnormal accumulation is also implicated in various neurological disorders.The olfactory bulb(OB),an early target in neurodegenerative diseases,acts as a gateway for environmental toxins and contains diverse neuronal populations with distinct roles.This study explored the cell-specific vulnerability to iron in the OB using a mouse model of intranasal administration of ferric ammonium citrate(FAC).Olfactory function was assessed through olfactory discrimination tests,while iron levels in OB tissues,cerebrospinal fluid(CSF),and serum were quantified using inductively coupled plasma mass spectrometry(ICP-MS),immunohistochemical staining,and iron assays.Transcriptomic changes and immune responses were assessed using RNA sequencing and immune cell infiltration analysis.Results showed that intranasal FAC administration impaired olfactory function,accompanied by iron deposition in the olfactory mucosa and OB,as well as damage to olfactory sensory neurons.Notably,these effects occurred without elevations in CSF or serum iron levels.OB iron accumulation activated multiple immune cells,including microglia and astrocytes,but did not trigger ferroptosis.Spatial transcriptomic sequencing of healthy adult mouse OBs revealed significant cellular heterogeneity,with an abundance of neuroglia and neurons.Among neurons,GABAergic neurons were the most prevalent,followed by glutamatergic and dopaminergic neurons,while cholinergic and serotonergic neurons were sparsely distributed.Under iron-stressed conditions,oligodendrocytes,dopaminergic neurons,and glutamatergic neurons exhibited significant damage,while GABAergic neurons remained unaffected.These findings highlight the selective vulnerability of neuronal and glial populations to iron-induced stress,offering novel insights into the loss of specific cell types in the OB during iron dysregulation.展开更多
The olfactory bulb(OB)is the first relay station in the olfactory system and functions as a crucial hub.It can represent odor information precisely and accurately in an ever-changing environment.As the only output neu...The olfactory bulb(OB)is the first relay station in the olfactory system and functions as a crucial hub.It can represent odor information precisely and accurately in an ever-changing environment.As the only output neurons in the OB,mitral/tufted cells encode information such as odor identity and concentration.Recently,the neural strategies and mechanisms underlying odor representation and encoding in the OB have been investigated extensively.Here we review the main progress on this topic.We first review the neurons and circuits involved in odor representation,including the different cell types in the OB and the neural circuits within and beyond the OB.We will then discuss how two different coding strategies—spatial coding and temporal coding—work in the rodent OB.Finally,we discuss potential future directions for this research topic.Overall,this review provides a comprehensive description of our current understanding of how odor information is represented and encoded by mitral/tufted cells in the OB.展开更多
Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extract...Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extracts as an antibulbing substance,the amount of which was synchronized with the bulb formation.Since allene oxide synthase inhibitor canceled the antibulbing activity ofα-linolenic acid,it was disclosed that jasmonic acid concerns this regulation.Structure-activity-relationship study revealed that its(3R,7S)stereochemistry is necessary for showing its antibulbing activity.It is concluded that(3R,7S)-jasmonate derived fromα-linolenic acid actually participates in the regulation of bulb formation.展开更多
A new natural product (1) together with 26 know compounds were isolated from the Bulbs of Ornithogalum caudatum. Their structures were established on the basis of spectral analyses as n-butyl pyroglutamate (1), nonade...A new natural product (1) together with 26 know compounds were isolated from the Bulbs of Ornithogalum caudatum. Their structures were established on the basis of spectral analyses as n-butyl pyroglutamate (1), nonadecyl alcohol(2), eicosanol(3), behenic acid(4), b-sitosterol(5), stigmasterol(6), glycerol 1-monocerotate(7), pyrocatechol(8), p-ethoxybenzoic acid(9), p-coumarinic acid(10), protocatechuric acid(11), ursolic acid(12), betulinic acid(13), fumaric acid(14), succinic acid(15), uracil(16), xanthine(17), quercetin(18), kaempferol (19), isorham-netin(20), adenosine(21), daucosterol(22), stigmasterol 3-O-b-D-glucopyranoside(23), quercetin 3-O-b-D-glucopyra-noside(24), kaempferol 3-O-b-D-glucopyranoside(25), rutin(26), and kaempferol 3-O-b-rutinoside(27). All of them, except compound 5, were isolated from this plant for the first time.展开更多
With different parts of bulb scale as explants, the proliferation method of Guizhou Lilium brownii were studied with 3% sodium hypochlorite and MS medium with different concentrations of hormones. The results show tha...With different parts of bulb scale as explants, the proliferation method of Guizhou Lilium brownii were studied with 3% sodium hypochlorite and MS medium with different concentrations of hormones. The results show that it is feasible to disinfect the bulbs of Lilium brownii with 3% sodium hypoehlorite, moreover, the sodium hypochlorite is very cheap and harmless to researchers, experimental materials and environment. MS ＋ NAA 0.3 mg/L ＋ 6-BA 1.5 mg/L is optimum for the induction of bulbs and, the basal part of Lilium brownie is the optimum explants. After culture for 25 d on the same medium, the tube bulbs could be obtained with the characteristics of high propagation coefficient, strong and new roots. The survival rate is over 90% for transplantation of tube bulbs with diameter between 1-2cm. The method developed in the present study can proliferate abundant Lilium brownii seedling in short time.展开更多
文摘Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. Moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased complexity and restructuring of neural network structures, as well as the addition of new granule granule cells that aid in olfactory adaptation. Additionally, the manuscript underscores the importance of employing precise methodologies to elucidate the specific roles of adult neurogenesis amidst conflicting data and varying experimental paradigms. Understanding these processes is essential for gaining insights into the complexities of olfactory function and behavior.
基金supported by the National Natural Science Foundation of China (32471188,32170984,82301787)。
文摘Iron is the most abundant transition metal in the brain and is essential for brain development and neuronal function;however,its abnormal accumulation is also implicated in various neurological disorders.The olfactory bulb(OB),an early target in neurodegenerative diseases,acts as a gateway for environmental toxins and contains diverse neuronal populations with distinct roles.This study explored the cell-specific vulnerability to iron in the OB using a mouse model of intranasal administration of ferric ammonium citrate(FAC).Olfactory function was assessed through olfactory discrimination tests,while iron levels in OB tissues,cerebrospinal fluid(CSF),and serum were quantified using inductively coupled plasma mass spectrometry(ICP-MS),immunohistochemical staining,and iron assays.Transcriptomic changes and immune responses were assessed using RNA sequencing and immune cell infiltration analysis.Results showed that intranasal FAC administration impaired olfactory function,accompanied by iron deposition in the olfactory mucosa and OB,as well as damage to olfactory sensory neurons.Notably,these effects occurred without elevations in CSF or serum iron levels.OB iron accumulation activated multiple immune cells,including microglia and astrocytes,but did not trigger ferroptosis.Spatial transcriptomic sequencing of healthy adult mouse OBs revealed significant cellular heterogeneity,with an abundance of neuroglia and neurons.Among neurons,GABAergic neurons were the most prevalent,followed by glutamatergic and dopaminergic neurons,while cholinergic and serotonergic neurons were sparsely distributed.Under iron-stressed conditions,oligodendrocytes,dopaminergic neurons,and glutamatergic neurons exhibited significant damage,while GABAergic neurons remained unaffected.These findings highlight the selective vulnerability of neuronal and glial populations to iron-induced stress,offering novel insights into the loss of specific cell types in the OB during iron dysregulation.
基金supported by the National Natural Science Foundation of China(Nos.32271055 and 32070995)the Jiangsu Province Innovative and Entrepreneurial Team Program,and the Guangdong Medical University(No.GDMUB2022048),China.
文摘The olfactory bulb(OB)is the first relay station in the olfactory system and functions as a crucial hub.It can represent odor information precisely and accurately in an ever-changing environment.As the only output neurons in the OB,mitral/tufted cells encode information such as odor identity and concentration.Recently,the neural strategies and mechanisms underlying odor representation and encoding in the OB have been investigated extensively.Here we review the main progress on this topic.We first review the neurons and circuits involved in odor representation,including the different cell types in the OB and the neural circuits within and beyond the OB.We will then discuss how two different coding strategies—spatial coding and temporal coding—work in the rodent OB.Finally,we discuss potential future directions for this research topic.Overall,this review provides a comprehensive description of our current understanding of how odor information is represented and encoded by mitral/tufted cells in the OB.
基金Supported by the Naito FoundationGrant-in-Aid for Scientific Research (22K05448)from Japan Society for the Promotion of Science.
文摘Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extracts as an antibulbing substance,the amount of which was synchronized with the bulb formation.Since allene oxide synthase inhibitor canceled the antibulbing activity ofα-linolenic acid,it was disclosed that jasmonic acid concerns this regulation.Structure-activity-relationship study revealed that its(3R,7S)stereochemistry is necessary for showing its antibulbing activity.It is concluded that(3R,7S)-jasmonate derived fromα-linolenic acid actually participates in the regulation of bulb formation.
基金This work was supported by the Ministry of Science and Technology of China (96-901-05-266).
文摘A new natural product (1) together with 26 know compounds were isolated from the Bulbs of Ornithogalum caudatum. Their structures were established on the basis of spectral analyses as n-butyl pyroglutamate (1), nonadecyl alcohol(2), eicosanol(3), behenic acid(4), b-sitosterol(5), stigmasterol(6), glycerol 1-monocerotate(7), pyrocatechol(8), p-ethoxybenzoic acid(9), p-coumarinic acid(10), protocatechuric acid(11), ursolic acid(12), betulinic acid(13), fumaric acid(14), succinic acid(15), uracil(16), xanthine(17), quercetin(18), kaempferol (19), isorham-netin(20), adenosine(21), daucosterol(22), stigmasterol 3-O-b-D-glucopyranoside(23), quercetin 3-O-b-D-glucopyra-noside(24), kaempferol 3-O-b-D-glucopyranoside(25), rutin(26), and kaempferol 3-O-b-rutinoside(27). All of them, except compound 5, were isolated from this plant for the first time.
基金Supported by the Nomarch Funds for Excellent Science and Technology Teachers of Guizhou Province(S2004-17)the Special Foundation for Im-proving Scientific Research Condition of Guizhou Province(Q2005-4)the Doctor Startup of Guiyang Medical College(C2005-6)~~
文摘With different parts of bulb scale as explants, the proliferation method of Guizhou Lilium brownii were studied with 3% sodium hypochlorite and MS medium with different concentrations of hormones. The results show that it is feasible to disinfect the bulbs of Lilium brownii with 3% sodium hypoehlorite, moreover, the sodium hypochlorite is very cheap and harmless to researchers, experimental materials and environment. MS ＋ NAA 0.3 mg/L ＋ 6-BA 1.5 mg/L is optimum for the induction of bulbs and, the basal part of Lilium brownie is the optimum explants. After culture for 25 d on the same medium, the tube bulbs could be obtained with the characteristics of high propagation coefficient, strong and new roots. The survival rate is over 90% for transplantation of tube bulbs with diameter between 1-2cm. The method developed in the present study can proliferate abundant Lilium brownii seedling in short time.
