Response features of mitral cells in the olfactory bulb were examined using principal component analysis to determine whether they contain information about odorant stimuli.Using microwire electrode array to record fr...Response features of mitral cells in the olfactory bulb were examined using principal component analysis to determine whether they contain information about odorant stimuli.Using microwire electrode array to record from the olfactory bulb in freely breathing anesthetized rats,we recorded responses of different mitral cells to saturated vapor of anisole(1 M),carvone(1 M),isobutanol(1 M),citral(1 M)and isoamyl actate(1 M).The responses of single mitral cells to the same odorant varied over time.The response profiles showed similarity during certain amount of period,which indicated that the response was not only depended on odor itself but also associated with context.Furthermore,the responses of single mitral cell to different odorants were observed with difference in firing rate.In order to recognize different odorant stimuli,we apply four cells as a sensing group for classification using principal component analysis.Features of each cell’s response describing both temporal and frequency characteristics were selected.The results showed that five different single molecular odorants can be distinguished from each other.These data suggest that action potentials of mitral cells may play a role in odor coding.展开更多
The purpose of this article is to detect sex and age difference in the structure of the olfactory bulb in dogs by histological methods. The thickness of the olfactory bulbs layers and its main cells were analyzed comp...The purpose of this article is to detect sex and age difference in the structure of the olfactory bulb in dogs by histological methods. The thickness of the olfactory bulbs layers and its main cells were analyzed comparatively with the methods of HE-staining and statistics, through which we studied the development course of dogs＇ olfactory bulb and the structural differences which affect the olfaction in both males and females. The results showed that between both male and female juveniles and adult males and females, the difference in thickness of each layer is not significant. But the difference in quantity of mitral cells between adult males and females was significant. Meanwhile, the structure of every layer in juvenile dogs was apparent while the volume and the weight of adult dogs＇ olfactory bulb and each layer＇s width increased significantly. On the other hand, the density of each layer＇s cells decreased apparently. Our results demonstrated that the olfactory bulb developed with age, and the apparent differences in morphology and quantity of mitral cells between males and females may be one of the reasons leading to the sexual variations of olfactory sensitivity.展开更多
Fiber photometry is a recently-developed method that indirectly measures neural activity by monitoring Ca^(2+)signals in genetically-identified neuronal populations.Although fiber photometry is widely used in neurosci...Fiber photometry is a recently-developed method that indirectly measures neural activity by monitoring Ca^(2+)signals in genetically-identified neuronal populations.Although fiber photometry is widely used in neuroscience research,the relationship between the recorded Ca^(2+)signals and direct electrophysiological measurements of neural activity remains elusive.Here,we simultaneously recorded odor-evoked Ca^(2+)and electrophysiological signals[single-unit spikes and local field potentials(LFPs)]from mitral/tufted cells in the olfactory bulb of awake,head-fixed mice.Odors evoked responses in all types of signal but the response characteristics(e.g.,type of response and time course)differed.The Ca^(2+)signal was correlated most closely with power in theβ-band of the LFP.The Ca^(2+)signal performed slightly better at odor classification than high-γoscillations,worse than single-unit spikes,and similarly toβoscillations.These results provide new information to help researchers select an appropriate method for monitoring neural activity under specific conditions.展开更多
Responses of 302 mitral/tufted (M/T) cells in the olfactory bulb were recorded from 42 anesthetized freely breathing rats using a 16-channel microwire electrode array.Saturated vapors of four pure chemicals,anisole,ca...Responses of 302 mitral/tufted (M/T) cells in the olfactory bulb were recorded from 42 anesthetized freely breathing rats using a 16-channel microwire electrode array.Saturated vapors of four pure chemicals,anisole,carvone,citral and isoamyl acetate were applied.After aligning spike trains to the initial phase of the inhalation after odor onset,the responses of M/T cells showed transient temporal features including excitatory and inhibitory patterns.Both odor-evoked patterns indicated that mammals recognize odors within a short respiration cycle after odor stimulus.Due to the small amount of information received from a single cell,we pooled results from all responsive M/T cells to study the ensemble activity.The firing rates of the cell ensembles were computed over 100 ms bins and population vectors were constructed.The high dimension vectors were condensed into three dimensions for visualization using principal component analysis.The trajectories of both excitatory and inhibitory cell ensembles displayed strong dynamics during odor stimulation.The distances among cluster centers were enlarged compared to those of the resting state.Thus,we presumed that pictures of odor information sent to higher brain regions were depicted and odor discrimination was completed within the first breathing cycle.展开更多
基金This research is supported by the National Natural Science Foundation of China(Grant 60725102).
文摘Response features of mitral cells in the olfactory bulb were examined using principal component analysis to determine whether they contain information about odorant stimuli.Using microwire electrode array to record from the olfactory bulb in freely breathing anesthetized rats,we recorded responses of different mitral cells to saturated vapor of anisole(1 M),carvone(1 M),isobutanol(1 M),citral(1 M)and isoamyl actate(1 M).The responses of single mitral cells to the same odorant varied over time.The response profiles showed similarity during certain amount of period,which indicated that the response was not only depended on odor itself but also associated with context.Furthermore,the responses of single mitral cell to different odorants were observed with difference in firing rate.In order to recognize different odorant stimuli,we apply four cells as a sensing group for classification using principal component analysis.Features of each cell’s response describing both temporal and frequency characteristics were selected.The results showed that five different single molecular odorants can be distinguished from each other.These data suggest that action potentials of mitral cells may play a role in odor coding.
基金National Natural Science Foundation of China (30370218)Shan-dong Science Fund for Distinguished Young Scholars(2005BS02005)Science Foundation for Excellent Scholars of Ministry of Education of China (NCET-07-0507)
文摘The purpose of this article is to detect sex and age difference in the structure of the olfactory bulb in dogs by histological methods. The thickness of the olfactory bulbs layers and its main cells were analyzed comparatively with the methods of HE-staining and statistics, through which we studied the development course of dogs＇ olfactory bulb and the structural differences which affect the olfaction in both males and females. The results showed that between both male and female juveniles and adult males and females, the difference in thickness of each layer is not significant. But the difference in quantity of mitral cells between adult males and females was significant. Meanwhile, the structure of every layer in juvenile dogs was apparent while the volume and the weight of adult dogs＇ olfactory bulb and each layer＇s width increased significantly. On the other hand, the density of each layer＇s cells decreased apparently. Our results demonstrated that the olfactory bulb developed with age, and the apparent differences in morphology and quantity of mitral cells between males and females may be one of the reasons leading to the sexual variations of olfactory sensitivity.
基金the National Natural Science Foundation of China(31872771,32070995,and 31900713)the National Demonstration Center for Experimental Basic Medical Science Education(Xuzhou Medical University).
文摘Fiber photometry is a recently-developed method that indirectly measures neural activity by monitoring Ca^(2+)signals in genetically-identified neuronal populations.Although fiber photometry is widely used in neuroscience research,the relationship between the recorded Ca^(2+)signals and direct electrophysiological measurements of neural activity remains elusive.Here,we simultaneously recorded odor-evoked Ca^(2+)and electrophysiological signals[single-unit spikes and local field potentials(LFPs)]from mitral/tufted cells in the olfactory bulb of awake,head-fixed mice.Odors evoked responses in all types of signal but the response characteristics(e.g.,type of response and time course)differed.The Ca^(2+)signal was correlated most closely with power in theβ-band of the LFP.The Ca^(2+)signal performed slightly better at odor classification than high-γoscillations,worse than single-unit spikes,and similarly toβoscillations.These results provide new information to help researchers select an appropriate method for monitoring neural activity under specific conditions.
基金Project (Nos. 30970765 and 81027003) supported by the National Natural Science Foundation of China
文摘Responses of 302 mitral/tufted (M/T) cells in the olfactory bulb were recorded from 42 anesthetized freely breathing rats using a 16-channel microwire electrode array.Saturated vapors of four pure chemicals,anisole,carvone,citral and isoamyl acetate were applied.After aligning spike trains to the initial phase of the inhalation after odor onset,the responses of M/T cells showed transient temporal features including excitatory and inhibitory patterns.Both odor-evoked patterns indicated that mammals recognize odors within a short respiration cycle after odor stimulus.Due to the small amount of information received from a single cell,we pooled results from all responsive M/T cells to study the ensemble activity.The firing rates of the cell ensembles were computed over 100 ms bins and population vectors were constructed.The high dimension vectors were condensed into three dimensions for visualization using principal component analysis.The trajectories of both excitatory and inhibitory cell ensembles displayed strong dynamics during odor stimulation.The distances among cluster centers were enlarged compared to those of the resting state.Thus,we presumed that pictures of odor information sent to higher brain regions were depicted and odor discrimination was completed within the first breathing cycle.
