Limits...
Nasal chemosensory-stimulation evoked activity patterns in the rat trigeminal ganglion visualized by in vivo voltage-sensitive dye imaging.

Rothermel M, Ng BS, Grabska-Barwińska A, Hatt H, Jancke D - PLoS ONE (2011)

Bottom Line: Mammalian nasal chemosensation is predominantly mediated by two independent neuronal pathways, the olfactory and the trigeminal system.Within the early olfactory system, spatiotemporal responses of the olfactory bulb to various odorants have been mapped in great detail.Application of different chemical stimuli to the nasal cavity elicited distinct, stimulus-category specific, spatiotemporal activation patterns that comprised activated as well as suppressed areas.

View Article: PubMed Central - PubMed

Affiliation: Lehrstuhl für Zellphysiologie, Ruhr-Universität, Bochum, Germany.

ABSTRACT
Mammalian nasal chemosensation is predominantly mediated by two independent neuronal pathways, the olfactory and the trigeminal system. Within the early olfactory system, spatiotemporal responses of the olfactory bulb to various odorants have been mapped in great detail. In contrast, far less is known about the representation of volatile chemical stimuli at an early stage in the trigeminal system, the trigeminal ganglion (TG), which contains neurons directly projecting to the nasal cavity. We have established an in vivo preparation that allows high-resolution imaging of neuronal population activity from a large region of the rat TG using voltage-sensitive dyes (VSDs). Application of different chemical stimuli to the nasal cavity elicited distinct, stimulus-category specific, spatiotemporal activation patterns that comprised activated as well as suppressed areas. Thus, our results provide the first direct insights into the spatial representation of nasal chemosensory information within the trigeminal ganglion imaged at high temporal resolution.

Show MeSH

Related in: MedlinePlus

In vivo VSD imaging of chemosensory-stimulation evoked activity patterns in the rat TG.(A) Representative z-score maps (of a 2000–4800 ms-average) illustrating chemosensory-stimulation evoked TG activity pattern derived from an individual experiment. Citral and vanillin evoked low-amplitude activity across nearly the entire TG; scale bar = 1 mm. P, posterior; L, lateral. (B) Activity map comparison across animals demonstrates pattern stability and reproducibility. Overlay color code indicates number of animals showing activation (red) or suppression (blue) at the same trigeminal region (regions that are activated in some animals but suppressed in others offset each other.). The results are presented with two thresholds (z = ±2 (upper row) and ±1 (lower row)) due to a small scatter of activity patterns observed across animals. Contours in the CO2 condition (z>1) outline activated regions of individual animals; scale bar, 1 mm. Number in brackets indicates total number of animals for each condition. Arrows point to the common activation in the near-posterior, central-lateral trigeminal area (CO2 and ethanol condition). Arrowheads point to the anterior activity, elicited by ethanol but not CO2 stimulation (C) Local time course (ΔF/F) of activity from the highlighted regions in (A) (red trace = local time course from spot 1; green trace = spot 2; blue trace = spot 3, light colored areas = SD across single trials, n = 5 trials). See Figure S4 for the relationship of each local timecourse to the “blank” (no stimulus) condition. Dotted red line = stimulus onset (300 ms after recording started; stimulus stayed on till the end of the trial). Bottom black trace plots respiration cycle. Vertical red lines indicate response onset latencies.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3198387&req=5

pone-0026158-g003: In vivo VSD imaging of chemosensory-stimulation evoked activity patterns in the rat TG.(A) Representative z-score maps (of a 2000–4800 ms-average) illustrating chemosensory-stimulation evoked TG activity pattern derived from an individual experiment. Citral and vanillin evoked low-amplitude activity across nearly the entire TG; scale bar = 1 mm. P, posterior; L, lateral. (B) Activity map comparison across animals demonstrates pattern stability and reproducibility. Overlay color code indicates number of animals showing activation (red) or suppression (blue) at the same trigeminal region (regions that are activated in some animals but suppressed in others offset each other.). The results are presented with two thresholds (z = ±2 (upper row) and ±1 (lower row)) due to a small scatter of activity patterns observed across animals. Contours in the CO2 condition (z>1) outline activated regions of individual animals; scale bar, 1 mm. Number in brackets indicates total number of animals for each condition. Arrows point to the common activation in the near-posterior, central-lateral trigeminal area (CO2 and ethanol condition). Arrowheads point to the anterior activity, elicited by ethanol but not CO2 stimulation (C) Local time course (ΔF/F) of activity from the highlighted regions in (A) (red trace = local time course from spot 1; green trace = spot 2; blue trace = spot 3, light colored areas = SD across single trials, n = 5 trials). See Figure S4 for the relationship of each local timecourse to the “blank” (no stimulus) condition. Dotted red line = stimulus onset (300 ms after recording started; stimulus stayed on till the end of the trial). Bottom black trace plots respiration cycle. Vertical red lines indicate response onset latencies.

Mentions: (A) Trigeminal VSD activation pattern elicited by nasal ethanol application (z-score map, mean over 2,8 s). Arrow and arrowhead point to activated areas in the near-posterior, central-lateral and anterior trigeminal region, respectively; scale bar, 1 mm; P, posterior; L, lateral (B) Correlation of activity patterns to the location of nasal trigeminal neurons: Major clusters of nasal trigeminal neurons could be identified in the near-posterior, central-lateral region as well as in an anterior region on both sides relative to the midline of the ganglion (color code = number of animals showing infected cells at identical trigeminal regions). Arrows point to commonly activated area in CO2 and ethanol conditions; arrowheads to unique ethanol activity in VSD measurements (compare Figure 3A). Black trace = schematic TG outline; scale bar, 1 mm; Inserts: Representative fluorescence images showing traced nasal trigeminal neurons; scale bar, 20 µm.


Nasal chemosensory-stimulation evoked activity patterns in the rat trigeminal ganglion visualized by in vivo voltage-sensitive dye imaging.

Rothermel M, Ng BS, Grabska-Barwińska A, Hatt H, Jancke D - PLoS ONE (2011)

In vivo VSD imaging of chemosensory-stimulation evoked activity patterns in the rat TG.(A) Representative z-score maps (of a 2000–4800 ms-average) illustrating chemosensory-stimulation evoked TG activity pattern derived from an individual experiment. Citral and vanillin evoked low-amplitude activity across nearly the entire TG; scale bar = 1 mm. P, posterior; L, lateral. (B) Activity map comparison across animals demonstrates pattern stability and reproducibility. Overlay color code indicates number of animals showing activation (red) or suppression (blue) at the same trigeminal region (regions that are activated in some animals but suppressed in others offset each other.). The results are presented with two thresholds (z = ±2 (upper row) and ±1 (lower row)) due to a small scatter of activity patterns observed across animals. Contours in the CO2 condition (z>1) outline activated regions of individual animals; scale bar, 1 mm. Number in brackets indicates total number of animals for each condition. Arrows point to the common activation in the near-posterior, central-lateral trigeminal area (CO2 and ethanol condition). Arrowheads point to the anterior activity, elicited by ethanol but not CO2 stimulation (C) Local time course (ΔF/F) of activity from the highlighted regions in (A) (red trace = local time course from spot 1; green trace = spot 2; blue trace = spot 3, light colored areas = SD across single trials, n = 5 trials). See Figure S4 for the relationship of each local timecourse to the “blank” (no stimulus) condition. Dotted red line = stimulus onset (300 ms after recording started; stimulus stayed on till the end of the trial). Bottom black trace plots respiration cycle. Vertical red lines indicate response onset latencies.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198387&req=5

pone-0026158-g003: In vivo VSD imaging of chemosensory-stimulation evoked activity patterns in the rat TG.(A) Representative z-score maps (of a 2000–4800 ms-average) illustrating chemosensory-stimulation evoked TG activity pattern derived from an individual experiment. Citral and vanillin evoked low-amplitude activity across nearly the entire TG; scale bar = 1 mm. P, posterior; L, lateral. (B) Activity map comparison across animals demonstrates pattern stability and reproducibility. Overlay color code indicates number of animals showing activation (red) or suppression (blue) at the same trigeminal region (regions that are activated in some animals but suppressed in others offset each other.). The results are presented with two thresholds (z = ±2 (upper row) and ±1 (lower row)) due to a small scatter of activity patterns observed across animals. Contours in the CO2 condition (z>1) outline activated regions of individual animals; scale bar, 1 mm. Number in brackets indicates total number of animals for each condition. Arrows point to the common activation in the near-posterior, central-lateral trigeminal area (CO2 and ethanol condition). Arrowheads point to the anterior activity, elicited by ethanol but not CO2 stimulation (C) Local time course (ΔF/F) of activity from the highlighted regions in (A) (red trace = local time course from spot 1; green trace = spot 2; blue trace = spot 3, light colored areas = SD across single trials, n = 5 trials). See Figure S4 for the relationship of each local timecourse to the “blank” (no stimulus) condition. Dotted red line = stimulus onset (300 ms after recording started; stimulus stayed on till the end of the trial). Bottom black trace plots respiration cycle. Vertical red lines indicate response onset latencies.
Mentions: (A) Trigeminal VSD activation pattern elicited by nasal ethanol application (z-score map, mean over 2,8 s). Arrow and arrowhead point to activated areas in the near-posterior, central-lateral and anterior trigeminal region, respectively; scale bar, 1 mm; P, posterior; L, lateral (B) Correlation of activity patterns to the location of nasal trigeminal neurons: Major clusters of nasal trigeminal neurons could be identified in the near-posterior, central-lateral region as well as in an anterior region on both sides relative to the midline of the ganglion (color code = number of animals showing infected cells at identical trigeminal regions). Arrows point to commonly activated area in CO2 and ethanol conditions; arrowheads to unique ethanol activity in VSD measurements (compare Figure 3A). Black trace = schematic TG outline; scale bar, 1 mm; Inserts: Representative fluorescence images showing traced nasal trigeminal neurons; scale bar, 20 µm.

Bottom Line: Mammalian nasal chemosensation is predominantly mediated by two independent neuronal pathways, the olfactory and the trigeminal system.Within the early olfactory system, spatiotemporal responses of the olfactory bulb to various odorants have been mapped in great detail.Application of different chemical stimuli to the nasal cavity elicited distinct, stimulus-category specific, spatiotemporal activation patterns that comprised activated as well as suppressed areas.

View Article: PubMed Central - PubMed

Affiliation: Lehrstuhl für Zellphysiologie, Ruhr-Universität, Bochum, Germany.

ABSTRACT
Mammalian nasal chemosensation is predominantly mediated by two independent neuronal pathways, the olfactory and the trigeminal system. Within the early olfactory system, spatiotemporal responses of the olfactory bulb to various odorants have been mapped in great detail. In contrast, far less is known about the representation of volatile chemical stimuli at an early stage in the trigeminal system, the trigeminal ganglion (TG), which contains neurons directly projecting to the nasal cavity. We have established an in vivo preparation that allows high-resolution imaging of neuronal population activity from a large region of the rat TG using voltage-sensitive dyes (VSDs). Application of different chemical stimuli to the nasal cavity elicited distinct, stimulus-category specific, spatiotemporal activation patterns that comprised activated as well as suppressed areas. Thus, our results provide the first direct insights into the spatial representation of nasal chemosensory information within the trigeminal ganglion imaged at high temporal resolution.

Show MeSH
Related in: MedlinePlus