Journal: Frontiers in Neural Circuits

Article Title: Laminar-dependent effects of cortical state on auditory cortical spontaneous activity

doi: 10.3389/fncir.2012.00109

Figure Lengend Snippet: State-dependent and cell-type-specific spontaneous firing. (A) An example of pedunculopontine tegmental (PPT) nucleus stimulation and neural population activity in the auditory cortex. LFP, multiple single-units, spectrogram, and a history of low-frequency LFP power are shown. (B) Examples of morphologically identified pyramidal cells (PCs) and the effects of PPT stimulation on their spiking. Rasters show response of these cells to repeated PPT stimuli; lower graphs show peri-stimulus time histograms. (C) Modulation index of morphologically identified PCs and extracellularly classified single-units. L5slP, L5 slender PCs; L5tP, L5 thick PCs; sP and dP putative superficial and deep PCs, respectively; sFS and dFS, putative superficial and deep fast-spiking interneurons (FSs), respectively. * p < 0.05, ** p < 0.01, and *** p < 0.005 (signed-rank test). (D) Mean firing rate during the synchronized state plotted against that during the desynchronized state ( left column ) and modulation index ( right column ) for morphologically identified and putative PCs ( top row ), and putative FSs ( bottom row ). Solid lines in left panels correspond to equality; those in right panels are linear regression fits. Please note that linear fitting was done with a semi-logarithmic scale.

Article Snippet: In the visual cortex, basal forebrain stimulation causes a decrease in multiunit firing rates in superficial layers, but a mean increase in all others (Goard and Dan, ), largely consistent with our results; however, a second study (Niell and Stryker, ) found that running in a head-restrained condition (also expected to cause desynchronization) had little effect on spontaneous firing rates, except for a subset of putative FSs which showed a dramatic increase.

Techniques: Activity Assay

Journal: Frontiers in Neural Circuits

Article Title: Laminar-dependent effects of cortical state on auditory cortical spontaneous activity

doi: 10.3389/fncir.2012.00109

Figure Lengend Snippet: State-dependent and cell-type-specific spontaneous firing in unanesthetized animals. (A) Spontaneous shift of cortical states. The spectrogram ( top ) was computed from LFPs in the auditory cortex without auditory stimulation. The bottom panel indicates a history of total LFP power at 0–7 Hz. (B) MUA across layers and LFPs in the desynchronized ( left ) and synchronized states ( right ). (C) Modulation index of spontaneous population activity in putative L2/3 (0–500 μm from cortical surface) and L5 (800–1100 μm). * p < 0.05 ( t -test). (D) Modulation index of extracellularly classified single-unit activity (SUA) in putative L2/3 and L5. * p < 0.05 and ** p < 0.005 (signed-rank test). (E) Firing rate during the synchronized state plotted against that during the desynchronized state ( left ) and modulation index ( right ) for putative PCs and putative FSs. Solid line in left panel corresponds to equality; that in right panel is linear regression fit for putative PCs. Dotted line in right panel is linear fit for putative FSs. Linear fitting was done with a semi-logarithmic scale.

Article Snippet: In the visual cortex, basal forebrain stimulation causes a decrease in multiunit firing rates in superficial layers, but a mean increase in all others (Goard and Dan, ), largely consistent with our results; however, a second study (Niell and Stryker, ) found that running in a head-restrained condition (also expected to cause desynchronization) had little effect on spontaneous firing rates, except for a subset of putative FSs which showed a dramatic increase.

Techniques: Activity Assay