Journal
JOURNAL OF NEUROSCIENCE
Volume 28, Issue 8, Pages 1871-1881Publisher
SOC NEUROSCIENCE
DOI: 10.1523/JNEUROSCI.3948-07.2008
Keywords
conductance injection; dynamic clamp; local field potential; regular-spiking; fast-spiking; synchronization
Categories
Ask authors/readers for more resources
Gamma (gamma) oscillation, a hallmark of cortical activity during sensory processing and cognition, occurs during persistent, self-sustained activity or UP states, which are thought to be maintained by recurrent synaptic inputs to pyramidal cells. During neocortical UP states, excitatory regular spiking (RS) (pyramidal) cells and inhibitory fast spiking (FS) (basket) cells fire with distinct phase distributions relative to the gamma oscillation in the local field potential. Evidence suggests that gamma-modulated RS -> FS input serves to synchronize the interneurons and hence to generate gamma-modulated FS -> RS drive. How RS -> RS recurrent input shapes both self-sustained activity and gamma-modulated phasic firing, although, is unclear. Here, we investigate this by reconstructing gamma-modulated synaptic input to RS cells using the conductance injection (dynamic clamp) technique in cortical slices. We find that, to show lifelike gamma-modulated firing, RS cells require strongly gamma-modulated, low-latency inhibitory inputs from FS cells but little or no gamma-modulation from recurrent RS -> RS connections. We suggest that this demodulation of recurrent excitation, compared with inhibition, reflects several possible effects, including distributed propagation delays and integration of excitation over wider areas of cortex, and maximizes the capacity for representing information by the timing of recurrent excitation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available