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Jancke, D.

Publications and source records attributed to Jancke, D..

2 recordsLinked to original sources

Psychedelic 5-HT2A agonist increases spontaneous and evoked 5-Hz oscillations in visual and retrosplenial cortex

Visual perception appears largely stable in time. However, psychophysical studies have revealed that theta waves (4-8 Hz) can modulate perception and have been linked to various cognitive states and functions. Neither the contribution of theta waves to cortical activity nor their impact during aberrant brain states have been resolved at high spatiotemporal scales. Here, using cortex-wide population voltage imaging in awake mice, we found that bouts of 5-Hz oscillations in the visual cortex are accompanied by similar oscillations in the retrosplenial cortex, occurring both spontaneously and evoked by visual stimulation. Injection of psychotropic 5-HT2AR agonist induced a significant increase in spontaneous 5-Hz oscillations, and also increased the power, occurrence probability and temporal persistence of visually evoked 5-Hz oscillations. This modulation of 5-Hz oscillations in both cortical areas indicates a strengthening of top-down control of perception, supporting an underlying mechanism of perceptual filling and visual hallucinations.

neuroscience↗

Subtraction and division of visual cortical population responses by the serotonergic system

Normalization is a fundamental operation throughout neuronal systems to adjust dynamic range. In the visual cortex various cell circuits have been identified that provide the substrate for such a canonical function, but how these circuits are orchestrated remains unclear. Here we suggest the serotonergic (5-HT) system as another player involved in normalization. 5-HT receptors of different classes are co-distributed across different cortical cell types, but their individual contribution to cortical population responses is unknown. We combined wide-field calcium imaging of primary visual cortex (V1) with optogenetic stimulation of 5-HT neurons in mice dorsal raphe nucleus (DRN) -- the major hub for widespread release of serotonin across cortex -- in combination with selective 5-HT receptor blockers. While inhibitory (5-HT1A) receptors accounted for subtractive suppression of spontaneous activity, depolarizing (5-HT2A) receptors promoted divisive suppression of response gain. Added linearly, these components led to normalization of population responses over a range of visual contrasts.

neuroscience↗