Invitation Pizza Club
Tuesday November 10, 2009 at 13:00 at the ICNC
Speaker: Dani Rokni (Yarom's Lab)
The spatio-temporal organization of cerebellar
cortical responses
The most striking anatomical feature of the cerebellar cortex is the orthogonal
organization of Purkinje cell dendrites and their most numerous inputs – the parallel
fibers. This pathway is organized in a lattice like manner, where each parallel fiber
sequentially crosses the dendritic field of hundreds of Purkinje cells. The intuitive
view emerging from this arrangement is that mossy fibers that activate the parallel
fiber system will sequentially activate Purkinje cells, thus generating accurate time
intervals (“the beam hypothesis”).
We used voltage sensitive dye imaging and the isolated cerebellar preparation to
characterize the spatio-temporal organization of mossy and climbing fiber inputs to
the cerebellar cortex. Responses to climbing fiber activation where organized in
parasagittal strips on the cerebellar cortex, while mossy fiber activation generated
responses that were organized in radial patches. The latter argues against the beam
hypothesis.