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WORKSHOP ON:
CENTRAL PROBLEMS IN SINGLE CELL COMPUTATION
16-18 September 2002
By invitation only
Venue
B10 Seminar Room, Alexandra House, 17 Queen Square, London, WC1N 3AR
| Rapid induction of direction-selective receptive fields of
developing tectal neurons by moving visual stimuli |
| Florian Engert, Department of Molecular &
Cellular Biology, Harvard University, USA |
| Early developing connections undergo activity-dependent refinement,
a process by which the sensory experience exerts epigenetic influence on the development
of the nervous system. Whether and how the specific spatiotemporal pattern of
experience-evoked activity plays an instructive role in the refinement of the developing
circuit remains unclear. We here report that, in the developing Xenopus retinotectal
system, responses of tectal neurons evoked by moving visual stimuli can be
"trained" to become direction-sensitive within minutes after repetitive exposure
of the retina to moving stimuli in a particular direction. The induction of this
directional sensitivity depended on the speed of training stimuli, and required spiking of
the tectal neuron as well as the activation of N-methyl-D-aspartate (NMDA) subtype of
glutamate receptors. Thus visual experience can rapidly and specifically modify the
developing circuit according to the spatiotemporal pattern of visual stimuli and
spike-timing-dependent synaptic modification may serve as an underlying mechanism. |
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