Serotonin receptors are targets for drugs treating depression, obesity, and migraine headaches. Crystal structures of two serotonin receptor subtypes bound to antimigraine medications or a precursor of LSD reveal how subtle differences in ligand binding cause substantial differences in receptor signaling and biological responses. The structures show that the same ligand can activate one or both of the two main serotonin receptor signaling mechanisms, depending on which receptor it binds.
Two research teams independently determined the crystal structures of two serotonin receptors bound to antimigraine drugs or a precursor of LSD. The structures show that subtle differences in how ligands bind to these receptors lead to substantial differences in the signals generated and the resulting biological responses. The same ligand can activate one or both of the two main serotonin receptor signaling mechanisms, depending on which specific receptor it binds to.
Structured visual streams containing regularities—whether perceptual (shape, motion) or semantic (idioms)—dominate over unstructured streams in the competition for visual awareness during binocular rivalry. Perceptual- and semantic-level regularities produce rivalry advantages that dissociate: perceptual regularities operate via nonconscious temporal integration and are vulnerable to disruptions of the spatiotemporal integration window, whereas semantic regularities operate via conscious temporal integration and are not. These findings indicate that structure-guided information integration across time contributes to visual awareness through at least two distinct mechanisms, supporting theories that link integration to conscious experience.
Perception of eye gaze, which can occur outside conscious awareness, is influenced by what is held in working memory (WM). Using continuous flash suppression to render gaze invisible, the study found that suppressed gaze entered conscious awareness faster when its direction matched a face held in WM. This effect did not occur with passive viewing, ruling out simple perceptual priming. WM representations of head orientation also facilitated congruent gaze breakthrough, but WM representations of nonsocial cues like arrows did not. These findings indicate that WM acts as a top-down mechanism enhancing nonconscious gaze perception, suggesting a specialized process for social signals.