NPhys - Neurophysics Group | Gruppi e progetti di ricerca

Differential Coding of Fruit, Leaf, and Microbial Odours in the Brains of Drosophila suzukii and Drosophila melanogaster

Drosophila suzukii severely damages the production of berry and stone fruits in large parts of the world. Unlike D. melanogaster, which reproduces on overripe and fermenting fruits on the ground, D. suzukii prefers to lay its eggs in ripening fruits still on the plants. Flies locate fruit hosts by their odorant volatiles, which are detected and encoded by a highly specialised olfactory system before being translated into behaviour. The exact information-processing pathway is not yet fully understood, especially the evaluation of odour attractiveness. It is also unclear what differentiates the brains of D. suzukii and D. melanogaster to cause the crucial difference in host selection. We hypothesised that the basis for different behaviours is already formed at the level of the antennal lobe of D. suzukii and D. melanogaster by different neuronal responses to volatiles associated with ripe and fermenting fruit. We thus investigated by 3D in vivo two-photon calcium imaging how both species encoded odours from ripe fruits, leaves, fermented fruits, bacteria, and their mixtures in the antennal lobe. We then assessed their behavioural responses to mixtures of ripe and fermenting odours. The neural responses reflect species-dependent shifts in the odour code. In addition to this, morphological differences were also observed. However, this was not directly reflected in different behavioural responses to the odours tested.

Fluorescence Lifetime Microscopy: Focus on Metabolic Imaging

Hands-on workshop organized by FLIM Labs, Media System Lab, and CIMeC Event Schedule 10:00 Media System Lab Opening Francesco Girardi, PhD, Media SyStem Lab 10:15 Once in a Fluorescence Lifetime Francesco Cardarelli, PhD, Scuola Normale Superiore 10:45 FLIM for Metabolic Imaging Chiara Peres, PhD, CNR Bologna 11:15 Coffee Break 11:30 Hands-on session: basic principles of FLA Alessandro Rossetta, PhD, FLIM Labs 12:30 Lunch Break 14:00-17:00 Practical sessions: FLIM on 2-photon microscope Prof.

Parieto-Frontal networks mediate contextual influences in the appraisal of pain and disgust facial expressions

We appraise other people’s emotions by combining multiple sources of information, including somatic facial/body reactions and the surrounding context. A wealthy literature revealed how people take into account contextual information in the interpretation of facial expressions, but the mechanisms mediating such influence still need to be duly investigated. Across two experiments, we mapped the neural representations of distinct (but comparably unpleasant) negative states, pain and disgust, as conveyed by naturalistic facial expressions or contextual sentences. Negative expressions led to shared activity in fusiform gyrus and superior temporal sulcus. Instead, pain contexts recruited supramarginal, postcentral and insular cortex, whereas disgust contexts triggered the temporo-parietal cortex and hippocampus/amygdala. When pairing the two sources of information together, we found higher likelihood of classifying an expression according to the sentence preceding it. Furthermore, networks specifically involved in processing contexts were re-enacted whenever a face followed said context. Finally, the perigenual medial prefrontal cortex showed increased activity for consistent ( vs . inconsistent) face-contexts pairings, suggesting that it integrates state-specific information from the two sources. Overall, our study reveals the heterogeneous nature of face-context information integration, which operates both according to a state-general and state-specific principle, with the latter mediated by the perigenual medial prefrontal cortex. Significance Statement With the aid of controlled database and a comprehensive paradigm, our study provides new insights of the brain and behavioral processes mediating contextual influences on face emotion-specific processing. Our results reveal that context operates both in face-independent and face-conditional fashion, by biasing the interpretation of any face towards the state implied by associated context, and also triggering processes that monitor the consistency between the different sources of information. Overall, our study unveils key neural processes underlying the coding of state-specific information from both face and context and sheds new light on how they are integrated within the medial prefrontal cortex.

Influence of transient emotional episodes on affective and cognitive theory of mind

Abstract. Our emotions may influence how we interact with others. Previous studies have shown an important role of emotion induction in generating empathic reac

Associative Learning of Quantitative Mechanosensory Stimuli in Honeybees

The proboscis extension response (PER) has been widely used to evaluate honeybees’ (Apis mellifera) learning and memory abilities, typically by using odors and visual cues for the conditioned stimuli. Here we asked whether honeybees could learn to distinguish between different magnitudes of the same type of stimulus, given as two speeds of air flux. By taking advantage of a novel automated system for administering PER experiments, we determined that the bees were highly successful when the lower air flux was rewarded and less successful when the higher flux was rewarded. Importantly, since our method includes AI-assisted analysis, we were able to consider subthreshold responses at a high temporal resolution; this analysis revealed patterns of rapid generalization and slowly acquired discrimination between the rewarded and unrewarded stimuli, as well as indications that the high air flux may have been mildly aversive. The learning curve for these mechanosensory stimuli, at least when the lower flux is rewarded, more closely mimics prior data from olfactory PER studies rather than visual ones, possibly in agreement with recent findings that the insect olfactory system is also sensitive to mechanosensory information. This work demonstrates a new modality to be used in PER experiments and lays the foundation for deeper exploration of honeybee cognitive processes when posed with complex learning challenges.