Nasal Chemosensory-Stimulation Evoked Activity Patterns in the Rat Trigeminal Ganglion Visualized by In Vivo Voltage-Sensitive Dye Imaging

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

Properties of the avian visual pallium

Die Taube ist ein gängiges Tiermodell für Untersuchungen visueller Prozesse. Weitgehend unbekannt ist jedoch, wie ihr effizientes visuelles System einfachste Informationen verarbeitet. In der vorliegenden Studie wurde mittels spannungssensitiver Farbstoffe untersucht, wie grundlegende visuelle Parameter im Wulst der Taube verarbeitet werden. Es wurde gezeigt, dass Elevationen im visuellen Feld in der antero-posterioren Achse repräsentiert werden. Der Wulst zeigte keine Orientierungskarte, sondern eine Überrepräsentation vertikaler Orientierung; wahrscheinlich eine Anpassung an eine Überexposition von horizontalen Bewegungsvektoren durch das natürliche Verhalten der Taube. Außerdem wurde eine Kodierung für eine relative achromatische Luminanzänderung ermittelt, der eine Verstärkungsmodulation in zwei räumlich getrennten Domänen zugrunde liegt. Die Arbeit zeigt, wie die Anforderungen der Verarbeitung natürlicher Stimuli die zu Grunde liegende Gehirnorganisation beeinflussen können

Nasal chemosensory-stimulation evoked activity patterns in the rat trigeminal ganglion visualized by In Vivo\textit {In Vivo} voltage-sensitive dye imaging

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 $\textit {in vivo}$ 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