Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for sign...Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for signal transduction.The plasticity of spine morphologies provides a tunable handle to regulate calcium signal dynamics,allowing rapid regulation of protein expression necessary to establish and maintain synapses(Cornejo et al.,2022).If excitatory inputs were to be located primarily on dendritic shafts,dendrites would frequently short-circuit,preventing voltage signals from propagating(Cornejo et al.,2022).It is thus not surprising that the structural plasticity of dendritic spines is closely linked to synaptic plasticity and memory formation(Berry and Nedivi,2017).While comprehensive in vitro studies have been conducted,in vivo studies that directly tackle the mechanism of dendritic transport and translation in regulating spine plasticity spatiotemporally are limited.展开更多
Precise chemical cue presentation alongside advanced brainwide imaging techniques is important to the study of chemosensory processing in animals.Nevertheless,the dynamic nature of chemical-carrying media,such as wate...Precise chemical cue presentation alongside advanced brainwide imaging techniques is important to the study of chemosensory processing in animals.Nevertheless,the dynamic nature of chemical-carrying media,such as water or air,poses a significant challenge for delivering highly-controlled chemical flow to an animal subject.Moreover,contact-based cue manipulation and delivery easily shift the position of the animal subject,which is often undesirable for high-quality brain imaging.Additionally,more advanced interfacing tools that align with the diverse range of body part sizes of an animal,ranging from micrometer-scale neurons to meter-long limbs,are much needed.This is particularly crucial when dealing with dimensions that are beyond the reach of conventional experimental tools.展开更多
Photoacoustic microscopy(PAM)operating within the 1.7-μm absorption window holds great promise for the quantitative imaging of lipids in various biological tissues.Despite its potential,the effectiveness of lipid-bas...Photoacoustic microscopy(PAM)operating within the 1.7-μm absorption window holds great promise for the quantitative imaging of lipids in various biological tissues.Despite its potential,the effectiveness of lipid-based PAM has been limited by the performance of existing nanosecond laser sources at this wavelength.In this work,we introduce a 1725-nm hybrid optical parametric oscillator emitter(HOPE)characterized by a narrow bandwidth of 1.4 nm,an optical signal-to-noise ratio(OSNR)of approximately 34 dB,and a high spectral energy density of up to 480 n J/nm.This advanced laser source significantly enhances the sensitivity of photoacoustic imaging,allowing for the detailed visualization of intrahepatic lipid distributions with an impressive maximal contrast ratio of 23.6:1.Additionally,through segmentation-based analysis of PAM images,we were able to determine steatosis levels that align with clinical assessments,thereby demonstrating the potential of our system for high-contrast,label-free lipid quantification.Our findings suggest that the proposed 1725-nm HOPE source could be a powerful tool for biomedical research and clinical diagnostics,offering a substantial improvement over current technologies in the accurate and non-invasive assessment of lipid accumulation in tissues.展开更多
基金supported by the National Natural Science Foundation of China(NSFC/RGC/JRF N_HKU735/21)Research Grant Council of Hong Kong,China(17102120,17108821,17103922,C1024-22GF,C7074-21G)+1 种基金Health and Medical Research Fund(HMRF 09200966)(to CSWL)FRQS Postdoctoral Fellowship(to AHKF).
文摘Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for signal transduction.The plasticity of spine morphologies provides a tunable handle to regulate calcium signal dynamics,allowing rapid regulation of protein expression necessary to establish and maintain synapses(Cornejo et al.,2022).If excitatory inputs were to be located primarily on dendritic shafts,dendrites would frequently short-circuit,preventing voltage signals from propagating(Cornejo et al.,2022).It is thus not surprising that the structural plasticity of dendritic spines is closely linked to synaptic plasticity and memory formation(Berry and Nedivi,2017).While comprehensive in vitro studies have been conducted,in vivo studies that directly tackle the mechanism of dendritic transport and translation in regulating spine plasticity spatiotemporally are limited.
基金funded by a Croucher Innovation Award(CIA20CU01)from the Croucher Foundationthe General Research Fund(14100122)+4 种基金the Collaborative Research Fund(C6027-19GF&C7074-21GF)the Area of Excellence Scheme(AoE/M-604/16)of the Research Grants Councilthe University Grants Committee of Hong Kong,Chinathe Excellent Young Scientists Fund(Hong Kong and Macao,China)(82122001)from the National Natural Science Foundation of Chinathe Lo’s Family Charity Fund Limited(all to HK).
文摘Precise chemical cue presentation alongside advanced brainwide imaging techniques is important to the study of chemosensory processing in animals.Nevertheless,the dynamic nature of chemical-carrying media,such as water or air,poses a significant challenge for delivering highly-controlled chemical flow to an animal subject.Moreover,contact-based cue manipulation and delivery easily shift the position of the animal subject,which is often undesirable for high-quality brain imaging.Additionally,more advanced interfacing tools that align with the diverse range of body part sizes of an animal,ranging from micrometer-scale neurons to meter-long limbs,are much needed.This is particularly crucial when dealing with dimensions that are beyond the reach of conventional experimental tools.
基金Research Grants Council of the Hong Kong Special Administrative Region of China(HKU 17212824,HKU 17210522,HKU C7074-21G,HKU R7003-21,HKU 17205321)Innovation and Technology Commission of the Hong Kong SAR Government(MHP/073/20,MHP/057/21,Health@Inno HK program)Shenzhen Science Technology and Innovation Commission(SGDX20220530111403022)。
文摘Photoacoustic microscopy(PAM)operating within the 1.7-μm absorption window holds great promise for the quantitative imaging of lipids in various biological tissues.Despite its potential,the effectiveness of lipid-based PAM has been limited by the performance of existing nanosecond laser sources at this wavelength.In this work,we introduce a 1725-nm hybrid optical parametric oscillator emitter(HOPE)characterized by a narrow bandwidth of 1.4 nm,an optical signal-to-noise ratio(OSNR)of approximately 34 dB,and a high spectral energy density of up to 480 n J/nm.This advanced laser source significantly enhances the sensitivity of photoacoustic imaging,allowing for the detailed visualization of intrahepatic lipid distributions with an impressive maximal contrast ratio of 23.6:1.Additionally,through segmentation-based analysis of PAM images,we were able to determine steatosis levels that align with clinical assessments,thereby demonstrating the potential of our system for high-contrast,label-free lipid quantification.Our findings suggest that the proposed 1725-nm HOPE source could be a powerful tool for biomedical research and clinical diagnostics,offering a substantial improvement over current technologies in the accurate and non-invasive assessment of lipid accumulation in tissues.
