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.
Neuronal activity and connectivity define subcircuits in developing somatosensory cortex
|2012-07-02||Room: EE 1473|
Sensory information is transmitted with high fidelity across multiple synapses until it reaches the neocortex. There, individual neurons exhibit enormous variability in responses. The source of this diversity in output has been debated. Using transgenic mice expressing GFP coupled to the activity-dependent gene c-fos, we identified neurons with a history of elevated activity. Focusing on layer 4-2/3 connections, a site of strong excitatory drive at an initial stage of cortical processing, we find that fluorescently-tagged neurons receive significantly greater excitatory input compared to neighboring, unlabeled cells. Differential wiring of layer 2/3 neurons arises early in development and requires sensory input to be established. Stronger connection strength is not associated with evidence for recent synaptic plasticity, suggesting that these more active ensembles may be relatively stable. Paired recordings show fosGFP+ neurons spike at lower stimulus thresholds than neighboring, fosGFP- neurons. These data indicate that differences in circuit construction can underlie response heterogeneity amongst neocortical neurons.