Imaging räumlicher und zeitlicher Dynamik der Geruchstoffrepräsentation im Bulbus Olfactorius der Säugetiere mit einem neuen spannungsabhängigen Farbstoff

Spatial representations of odor identity and concentration are well described in the mammalian olfactory bulb. Their temporal dynamics have so far only been ex-amined in non-mammalian vertebrates and insects. Complex temporal response patterns have been described on a single cell level or with low spatial resolution using electroencephalography (EEG), however activity in several separate glomeruli could not be recorded simultaneously. The effects of odor identity and concentration on the spatio-temporal patterns can only be measured with a method that has both high spatial and temporal resolution. We chose the technique of voltage sensitive dye imaging (VSDI) to explore the spatio-temporal dynamics of odor-evoked activ-ity in the rat and mouse main olfactory bulb (MOB) with high temporal resolution. As established optical probes did not yield sufficient signals I first screened several new voltage sensitive dyes. The new voltage sensitive dye (RH 1838) allowed for measurements with relatively large fractional change (>0.5dF/F) compared to previous probes enabling me to measure odor evoked activity patterns without averaging across trials. The high temporal resolution of VSDI revealed odor specific sequences of glomerular activation. Increasing odor concentrations reduced response latencies, increased response amplitudes, and recruited new glomerular units. However the sequence of glomerular activation was maintained. Furthermore we found distributed MOB activity that was locked to the nasal respiration cycle. The spatial distribution of its amplitude and phase changed by sensory input in an odor specific manner. These data show that in the mammalian olfactory bulb odor identity and concentration are represented by spatio-temporal patterns, rather than spatial patterns alone.

Author dc:creator

• Spors, Hartwig

Contributors dc:contributor

• Sakmann, Bert

• Imaging
• Spannungsabhängiger Farbstoff
• Olfactory bulb
• Voltage sensitive dye imaging
• rat
• mouse
• odor

Repository record source_url

https://freidok.uni-freiburg.de/data/481

OAI identifier oai:identifier

oai:freidok.uni-freiburg.de:481