The activity of the Schaffer collaterals of hippocampal CA3 neurons and hippocampal CA1 neurons has been shown to increase after lfuid percussion injury. Diazepam can inhibit the hy-perexcitability of rat hippocampal ...The activity of the Schaffer collaterals of hippocampal CA3 neurons and hippocampal CA1 neurons has been shown to increase after lfuid percussion injury. Diazepam can inhibit the hy-perexcitability of rat hippocampal neurons after injury, but the mechanism by which it affects excitatory synaptic transmission remains poorly understood. Our results showed that diazepam treatment signiifcantly increased the slope of input-output curves in rat neurons after lfuid per-cussion injury. Diazepam signiifcantly decreased the numbers of spikes evoked by super stimuli in the presence of 15 μmol/L bicuculline, indicating the existence of inhibitory pathways in the injured rat hippocampus. Diazepam effectively increased the paired-pulse facilitation ratio in the hippocampal CA1 region following fluid percussion injury, reduced miniature excitatory postsynaptic potentials, decreased action-potential-dependent glutamine release, and reversed spontaneous glutamine release. These data suggest that diazepam could decrease the lfuid per-cussion injury-induced enhancement of excitatory synaptic transmission in the rat hippocampal CA1 area.展开更多
The mechanism of sex pheromone reception in the male cotton bollworm Helicoverpa armigera has been extensively studied because it has become an important model system for understanding insect olfaction.However,the pat...The mechanism of sex pheromone reception in the male cotton bollworm Helicoverpa armigera has been extensively studied because it has become an important model system for understanding insect olfaction.However,the pathways of pheromone processing from the antenna to the primary olfactory center in H.armigera have not yet been clarified.Here,the physiology and morphology of male H.armigera olfactory sensory neurons(OSNs)were studied using single sensillum recording along with anterograde filling and intracellular recording with retrograde filling.OSNs localized in type A sensilla responded to the major pheromone component cis-11-hexadecenal,and the axonal terminals projected to the cumulus(Cu)of the macroglomerular complex(MGC).The OSNs in type B sensilla respondcd to the bchavioral antagonist cis-9-tetradecenal,and the axonal terminals projected to the dorsomedial anterior(DMA)unit of the MGC.In type C sensilla,there were 2 OSNs:one that responded to cis-9-tetradecenal and cis-11-hexadecenol with the axonal terminals projecting to the DMA,and another that responded to the secondary pheromone components cis-9-hexadecenal and cis-9-tetradecenal with the axonal terminals projecting to the dorsomedial posterior(DMP)unit of the MGC.Type A and type B sensilla also housed the secondary OSNs,which were silent neurons with axonal terminals projected to the glomerulus G49 and DMP.Overall,the neural pathways that carry information on attractiveness and aversiveness in response to female pheromone components in H.armigera exhibit distinct projections to the MGC units.展开更多
The discharge patterns of neurons in auditory centers encode information about sounds.However,few studies have focused on the synaptic mechanisms underlying the shaping of discharge patterns using intracellular record...The discharge patterns of neurons in auditory centers encode information about sounds.However,few studies have focused on the synaptic mechanisms underlying the shaping of discharge patterns using intracellular recording techniques.Here,we investigated the discharge patterns of inferior collicular(IC)neurons using intracellular recordings to further elucidate the mechanisms underlying the shaping of discharge patterns.Under in vivo intracellular recording conditions,recordings were obtained from 66 IC neurons in 18 healthy adult mice(Mus musculus,Km)under free field-stimulation.Fiftyeight of these neurons fired bursts of action potentials(APs)to auditory stimuli and the remaining eight just generated local responses such as excitatory(n=4)or inhibitory(n=4)postsynaptic potentials.Based on the APs and subthreshold responses,the discharge patterns were classified into seven types:phasic(24/58,41.4%),phasic burst(8/58,13.8%),pauser(4/58,6.9%),phasic-pauser(1/58,1.7%),chopper(2/58,3.4%),primary-like tonic(14/58,24.1%)and sound-induced inhibitory(5/58,8.6%).We concluded that(1)IC neurons exhibit at least seven distinct discharge patterns;(2)inhibition participates in shaping the discharge pattern of most IC neurons and plays a role in sculpting the pattern,except for the primary-like tonic pattern which was not shapedby inhibition;and(3)local neural circuits are the likely structural basis that shapes the discharge patterns of IC neurons and can be formed either in the IC or in lower-level auditory structures.展开更多
The sense of taste plays a crucial role in herbivorous insects by discriminating nutrients from complex plant metabolic compounds.The peripheral coding of taste has been thoroughly studied in many insect species,but t...The sense of taste plays a crucial role in herbivorous insects by discriminating nutrients from complex plant metabolic compounds.The peripheral coding of taste has been thoroughly studied in many insect species,but the central gustatory pathways are poorly described.In the present study,we characterized single neurons in the gnathal ganglion of Helicoverpa armigera larvae using the intracellular recording/staining technique.We identified different types of neurons,including sensory neurons,interneurons,and motor neurons.The morphologies of these neurons were largely diverse and their arborizations seemingly covered the whole gnathal ganglion.The representation of the single neurons responding to the relevant stimuli of sweet and bitter cues showed no distinct patterns in the gnathal ganglion.We postulate that taste signals may be processed in a manner consistent with the principle of population coding in the gnathal ganglion of H.armigera larvae.展开更多
基金supported by the National Natural Science Foundation of China,No.81201984the Scientific Research Project of Shaanxi Provincial Health Department in China,No.2010E03the Yulin Municipal Science and Technology Research and Development Project,No.Sf12-06
文摘The activity of the Schaffer collaterals of hippocampal CA3 neurons and hippocampal CA1 neurons has been shown to increase after lfuid percussion injury. Diazepam can inhibit the hy-perexcitability of rat hippocampal neurons after injury, but the mechanism by which it affects excitatory synaptic transmission remains poorly understood. Our results showed that diazepam treatment signiifcantly increased the slope of input-output curves in rat neurons after lfuid per-cussion injury. Diazepam signiifcantly decreased the numbers of spikes evoked by super stimuli in the presence of 15 μmol/L bicuculline, indicating the existence of inhibitory pathways in the injured rat hippocampus. Diazepam effectively increased the paired-pulse facilitation ratio in the hippocampal CA1 region following fluid percussion injury, reduced miniature excitatory postsynaptic potentials, decreased action-potential-dependent glutamine release, and reversed spontaneous glutamine release. These data suggest that diazepam could decrease the lfuid per-cussion injury-induced enhancement of excitatory synaptic transmission in the rat hippocampal CA1 area.
基金supported by theNational Natural Science Foundation of China(U1604109,32130089,31861133019)the Program for Science and Technology Innovation Talents in Universities of Henan Province(19HASTITO11).
文摘The mechanism of sex pheromone reception in the male cotton bollworm Helicoverpa armigera has been extensively studied because it has become an important model system for understanding insect olfaction.However,the pathways of pheromone processing from the antenna to the primary olfactory center in H.armigera have not yet been clarified.Here,the physiology and morphology of male H.armigera olfactory sensory neurons(OSNs)were studied using single sensillum recording along with anterograde filling and intracellular recording with retrograde filling.OSNs localized in type A sensilla responded to the major pheromone component cis-11-hexadecenal,and the axonal terminals projected to the cumulus(Cu)of the macroglomerular complex(MGC).The OSNs in type B sensilla respondcd to the bchavioral antagonist cis-9-tetradecenal,and the axonal terminals projected to the dorsomedial anterior(DMA)unit of the MGC.In type C sensilla,there were 2 OSNs:one that responded to cis-9-tetradecenal and cis-11-hexadecenol with the axonal terminals projecting to the DMA,and another that responded to the secondary pheromone components cis-9-hexadecenal and cis-9-tetradecenal with the axonal terminals projecting to the dorsomedial posterior(DMP)unit of the MGC.Type A and type B sensilla also housed the secondary OSNs,which were silent neurons with axonal terminals projected to the glomerulus G49 and DMP.Overall,the neural pathways that carry information on attractiveness and aversiveness in response to female pheromone components in H.armigera exhibit distinct projections to the MGC units.
基金supported by grants from the National Natural Science Foundation of China (31070971,31000959)
文摘The discharge patterns of neurons in auditory centers encode information about sounds.However,few studies have focused on the synaptic mechanisms underlying the shaping of discharge patterns using intracellular recording techniques.Here,we investigated the discharge patterns of inferior collicular(IC)neurons using intracellular recordings to further elucidate the mechanisms underlying the shaping of discharge patterns.Under in vivo intracellular recording conditions,recordings were obtained from 66 IC neurons in 18 healthy adult mice(Mus musculus,Km)under free field-stimulation.Fiftyeight of these neurons fired bursts of action potentials(APs)to auditory stimuli and the remaining eight just generated local responses such as excitatory(n=4)or inhibitory(n=4)postsynaptic potentials.Based on the APs and subthreshold responses,the discharge patterns were classified into seven types:phasic(24/58,41.4%),phasic burst(8/58,13.8%),pauser(4/58,6.9%),phasic-pauser(1/58,1.7%),chopper(2/58,3.4%),primary-like tonic(14/58,24.1%)and sound-induced inhibitory(5/58,8.6%).We concluded that(1)IC neurons exhibit at least seven distinct discharge patterns;(2)inhibition participates in shaping the discharge pattern of most IC neurons and plays a role in sculpting the pattern,except for the primary-like tonic pattern which was not shapedby inhibition;and(3)local neural circuits are the likely structural basis that shapes the discharge patterns of IC neurons and can be formed either in the IC or in lower-level auditory structures.
基金This work was supported by the National Natural Science Foundation of China(31861133019,31672367)the Program for Science and Technology Innovation Talents in University of Henan Province(19HASTIT011)the Key Scientific and Technological Project of Henan Province of China(202102110072).
文摘The sense of taste plays a crucial role in herbivorous insects by discriminating nutrients from complex plant metabolic compounds.The peripheral coding of taste has been thoroughly studied in many insect species,but the central gustatory pathways are poorly described.In the present study,we characterized single neurons in the gnathal ganglion of Helicoverpa armigera larvae using the intracellular recording/staining technique.We identified different types of neurons,including sensory neurons,interneurons,and motor neurons.The morphologies of these neurons were largely diverse and their arborizations seemingly covered the whole gnathal ganglion.The representation of the single neurons responding to the relevant stimuli of sweet and bitter cues showed no distinct patterns in the gnathal ganglion.We postulate that taste signals may be processed in a manner consistent with the principle of population coding in the gnathal ganglion of H.armigera larvae.