Abstract
Gamma oscillations are thought to be critical for a number of behavioral functions, they occur in many regions of the brain and through a variety of mechanisms. Fast repetitive bursting (FRB) neurons in layer 2 of the cortex are able to drive gamma oscillations over long periods of time. Even though the oscillation is driven by FRB neurons, strong feedback within the rest of the cortex must modulate properties of the oscillation such as frequency and power. We used a highly detailed model of the cortex to determine how a cohort of 33 parameters controlling synaptic drive might modulate gamma oscillation properties. We were interested in determining not just the effects of parameters individually, but we also wanted to reveal interactions between parameters beyond additive effects. To prevent a combinatorial explosion in parameter combinations that might need to be simulated, we used a fractional factorial design (FFD) that estimated the effects of individual parameters and two parameter interactions. This experiment required only 4096 model runs. We found that the largest effects on both gamma power and frequency came from a complex interaction between efficacy of synaptic connections from layer 2 inhibitory neurons to layer 2 excitatory neurons and the parameter for the reciprocal connection. As well as the effect of the individual parameters determining synaptic efficacy, there was an interaction between these parameters beyond the additive effects of the parameters alone. The magnitude of this effect was similar to that of the individual parameters, predicting that it is physiologically important in setting gamma oscillation properties.
Highlights
Neuronal activity throughout the hippocampus and cortex is characterized by power in the gamma band (30–80 Hz)
Persistent gamma, oscillations are driven by fast repetitive bursting (FRB) neurons, known as chattering cells
FRB cells are pyramidal neurons which respond to current injections with bursts of high frequency action potentials but with a burst frequency in the gamma range
Summary
Neuronal activity throughout the hippocampus and cortex is characterized by power in the gamma band (30–80 Hz). A recent report has suggested that gamma oscillations may enhance information transmission (Sohal et al, 2009) These oscillations are found in the olfactory bulb (Adrian, 1942), hippocampus (Bragin et al, 1995) and in most regions of the cortex (Bouyer et al, 1981; Eckhorn et al, 1988). Persistent gamma, oscillations are driven by fast repetitive bursting (FRB) neurons, known as chattering cells. These oscillations are observed in slices perfused with carbachol or kainate (Buhl et al, 1998; Cunningham et al, 2004). There is likely to be a complex interaction between single FRB neuron properties, the microcircuit of coupled FRB neurons and the larger network
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
