Ventral tegmental area (VTA) dopaminergic neurons, which are well known for their central roles in reward and motivation-related behaviors, have been shown to participate in itch processing via their projection to the nucleus accumbens (NAc). However, the functional roles of different dopamine receptor subtypes in subregions of the NAc during itch processing remain unknown. With pharmacological approaches, we found that the blockade of dopamine D1 receptors (D1R), but not dopamine D2 receptors (D2R), in the lateral shell (LaSh) of the NAc impaired pruritogen-induced scratching behavior in male mice. In contrast, pharmacological activation of D2R in both the LaSh and medial shell (MeSh) of the NAc attenuated the scratching behavior induced by pruritogens. Consistently, we found that dopamine release, as detected by a dopamine sensor, was elevated in the LaSh rather than the MeSh of the NAc at the onset of scratching behavior. Furthermore, the elevation of dopamine release in the LaSh of the NAc persisted ev...

Detecting object boundaries is crucial for recognition, but how the process unfolds in visual cortex remains unknown. To study the problem faced by a hypothetical boundary cell, and to predict how cortical circuitry could produce a boundary cell from a population of conventional “simple cells”, we labeled 30,000 natural image patches and used Bayes’ rule to help determine how a simple cell should influence a nearby boundary cell depending on its relative offset in receptive field position and orientation. We identified three basic types of cell-cell interactions: rising and falling interactions with a range of slopes and saturation rates, as well as non-monotonic (bump-shaped) interactions with varying modes and amplitudes. Using simple models we show that a ubiquitous cortical circuit motif consisting of direct excitation and indirect inhibition – a compound effect we call "incitation" – can produce the entire spectrum of simple cell-boundary cell interactions found in our dataset. Moreover, we show that ...

Jing-Jing Liu, Katherine W. Eyring, Gabriele M. König, Evi Kostenis, and Richard W. Tsien (see pages [7707–7720][1]) Interest in hippocampal area CA2 has grown substantially since the area was discovered to have essential roles in social interaction. In particular, blocking output from dorsal

To ensure survival in a dynamic environment, the human neocortex monitors input streams from different sensory organs for important sensory events. Which principles govern whether different senses share common or modality-specific brain networks for sensory target detection? We examined whether complex targets evoke sustained supramodal activity while simple targets rely on modality-specific networks with short-lived supramodal contributions. In a series of hierarchical multisensory target detection studies (n=77, of either sex) using Electroencephalography, we applied a temporal cross-decoding approach to dissociate supramodal and modality-specific cortical dynamics elicited by rule-based global and feature-based local sensory deviations within and between the visual, somatosensory and auditory modality. Our data show that each sense implements a cortical hierarchy orchestrating supramodal target detection responses which operate at local and global timescales in successive processing stages. Across diffe...

In recent years research on natural speech processing has benefited from recognizing that low-frequency cortical activity tracks the amplitude envelope of natural speech. However, it remains unclear to what extent this tracking reflects speech-specific processing beyond the analysis of the stimulus acoustics. In the present study, we aimed to disentangle contributions to cortical envelope tracking that reflect general acoustic processing from those that are functionally related to processing speech. To do so, we recorded EEG from subjects as they listened to auditory chimeras, stimuli composed of the temporal fine structure of one speech stimulus modulated by the amplitude envelope (ENV) of another speech stimulus. By varying the number of frequency bands used in making the chimeras, we obtained some control over which speech stimulus was recognized by the listener. No matter which stimulus was recognized, envelope tracking was always strongest for the ENV stimulus, indicating a dominant contribution from ...

The perception of dynamic visual stimuli relies on two apparently conflicting perceptual mechanisms: rapid visual input must sometimes be integrated into unitary percepts but at other times must be segregated or parsed into separate objects or events. Though they have opposite effects on our perceptual experience, the deployment of spatial attention benefits both operations. Little is known about the neural mechanisms underlying this impact of spatial attention on temporal perception. Here, we record magnetoencephalography (MEG) in male and female humans to demonstrate that the deployment of spatial attention for the purpose of segregating or integrating visual stimuli impacts prestimulus oscillatory activity in retinotopic visual brain areas where the attended location is represented. Alpha band oscillations contralateral to an attended location are therefore faster than ipsilateral oscillations when stimuli appearing at this location will need to be segregated, but slower in expectation of the need for i...

Midfrontal theta (FMθ) in the human EEG is commonly viewed as a generic and homogeneous mechanism of cognitive control in general and conflict processing in particular. However, the role of FMθ in approach–avoidance conflicts and its cross-task relationship to simpler stimulus-response conflicts remain to be examined more closely. Therefore, we recorded EEG data while 59 healthy participants (49 female, 10 male) completed both an approach–avoidance task and a flanker task. Participants showed significant increases in FMθ power in response to conflicts in both tasks. To our knowledge, this is the first study to show a direct relationship between FMθ and approach–avoidance conflicts. Crucially, FMθ activity was task dependent and showed no cross-task correlation. To assess the possibility of multiple FMθ sources, we applied source separation [generalized eigendecomposition (GED)] to distinguish independent FMθ generators. The activity of the components showed a similar pattern and was again task specific. Ho...

It is well known that recent sensory experience influences perception, recently demonstrated by a phenomenon termed “serial dependence”. However, its underlying neural mechanisms are poorly understood. We measured ERP responses to pairs of stimuli presented randomly to the left or right hemifield. 17 male and female adults judged whether the upper or lower half of the grating had higher spatial frequency, independently of the horizontal position of the grating. This design allowed us to trace the memory signal modulating task performance and also the implicit memory signal associated with hemispheric position. Using classification techniques, we decoded the position of the current, previous stimuli and response from voltage scalp distributions of the current trial. Classification of previous responses reached full significance only 700 ms after presentation of current stimulus, consistent with retrieval of an activity-silent memory trace. Cross-condition classification accuracy of past responses (trained o...

It is well known that recent sensory experience influences perception, recently demonstrated by a phenomenon termed “serial dependence”. However, its underlying neural mechanisms are poorly understood. We measured ERP responses to pairs of stimuli presented randomly to the left or right hemifield. 17 male and female adults judged whether the upper or lower half of the grating had higher spatial frequency, independently of the horizontal position of the grating. This design allowed us to trace the memory signal modulating task performance and also the implicit memory signal associated with hemispheric position. Using classification techniques, we decoded the position of the current, previous stimuli and response from voltage scalp distributions of the current trial. Classification of previous responses reached full significance only 700 ms after presentation of current stimulus, consistent with retrieval of an activity-silent memory trace. Cross-condition classification accuracy of past responses (trained o...