Seminars are open to all visitors and start Monday at 16:00 sharp. Coffee and tea will be served from 15:45. The seminar series lectures are in a colloquiumzaal at the third floor (entrance level) of the Faculty building of Erasmus MC.
Fritjof Helmchen
Neuronal population responses revealed by in vivo two-photon microscopy.
| 2009-12-07 | Room: Ae 406 |
Functional imaging using two-photon microscopy is a promising tool for probing spatiotemporal activity patterns in ensembles of well-identified neurons in the living brain. Here I will report on several recent advances in the field of in vivo calcium imaging from neuronal populations. First, I will present a 3D laser scanning method, which allows monitoring of cell activities in volumes of about 250 micron side lengths at 10 Hz (several hundred cells in total). I will show application examples of 3D imaging from rodent barrel cortex. Second, I will introduce a non-mechanical (acousto-optic) scanning approach enabling high-speed two-photon imaging from neuronal populations (200-500 Hz from 30-100 neurons). Spike times can be reconstructed from the calcium measurements with 10 ms and better precision. This scan technology thus promises optical probing of precisely-timed spike sequences in neuronal ensembles in vivo. Finally, we have begun to express genetically-encoded calcium indicators in superficial layers of cortex, aiming at long-term repeated functional interrogation of the same neuronal populations. In summary, we expect these advances to help elucidate the correlation of activity patterns in neuronal ensembles with behavior.