Figure 4. Behavioural modulation of gamma synchrony.
A) Fine odour discrimination is associated with stronger gamma oscillations in the rat olfactory bulb (top: wide-band and gamma filtered LFP traces from rat olfactory bulb and its main target region, the piriform cortex, around the time of odour presentation) compared to coarse odour discrimination (bottom blue and red curves are average power spectra for olfactory bulb responses during fine and coarse odour discrimination respectively; 166. B) Monkey higher-order visual cortex (V4) displays synchronized gamma oscillations with primary visual cortex (V1) neural population representing behaviourally relevant visual stimulus, but not those linked to irrelevant stimulus 107. The plots on the bottom indicates directional influence of different areas within V1 on V4 gamma oscillations (as supported by Granger causality) depending on which of two simultaneously presented grating stimuli the monkey was attending to. C) Synchronized fast gamma oscillations appear in the rat dentate gyrus and medial entorhinal cortex during spatial learning (top). However, during object learning, coherent gamma oscillations of slower frequency appear between the dentate gyrus and lateral entorhinal cortex (bottom) 93. Plots on the right show the increase in LFP-LFP gamma synchrony between rat entorhinal cortical areas and the hippocampal dentate gyrus during different learning tasks as compared to baseline conditions.