Insect Cognitive Neuroethology (ICON)
The team studies the rules and mechanisms underlying experience-dependent plasticity in insect models, in particular honey bees. Using an integrative neuroscience approach, we aim at characterizing the neural bases of cognitive processing in these animals, focusing on various sensory modalities and behavioral contexts.
Although, there is a common perception that larger brains mediate higher cognitive capacity, bees demonstrate that sophisticated cognition is possible with miniature brains. They display higher-order learning such as categorization, non-linear discriminations, concept learning and numerosity, which are unique among insects. These capacities are mediated by a miniature brain with only 950 000 neurons, which is tractable in the laboratory.
Left : honey bee brain ; right : a mushroom body, a higher-older structure in the bee brain
In our research, we adopt conceptual frameworks from experimental psychology and neuroethology to study the complexity of insect cognition, focusing on questions revolving around visual, olfactory and gustatory learning and memory. We use behavioral approaches, which led to the establishment of various novel protocols for insect conditioning, as well as neural approaches, combining multiple invasive techniques to record neural activity in the bee brain (calcium imaging recordings, electrophysiology and neuropharmacological interference, among others). Molecular tools are also used to unveil the molecular cascades and genetic architectures underlying cognitive processing in bees. Our work has also led to the establishment of virtual reality scenarios for honey bees in which their visual learning and decision-making are studied.
ERC Advanced Grant COGNIBRAINS
Our current breakthrough establishing virtual-reality protocols for tethered honeybees offers a unique opportunity to uncover the minimal circuits that mediate higher-order forms of cognitive processing in the brain of a behaving bee. We have recently shown that bees learn to solve elemental and non-elemental problems in this experimental context, which allows integrating behavioral, neurobiological and computational approaches to unravel the neural mechanisms underlying non- elemental learning in the honeybee.
We combine behavioral recordings of bees learning non-linear discriminations and relational rules in a virtual reality environment, with access to their brain via multi- photon calcium imaging and multielectrode recordings of neural populations. Our goal is to determine the neural circuits of elemental and non-elemental visual learning along the visual circuits of the bee brain, and the necessity and sufficiency of these circuits for these capacities.
Appetitive decisions and central gustatory processingin the bee brain
Gabriela de Brito Sanchez
We aim at decrypting central-taste neuromodulation by focusing on the facilitatory or inhibitory effects of biogenic amines such as dopamine, octopamine, tyramine and serotonin, and of neuropeptides such as sNPF on appetitive responses and decision making.
We are interested by neuropeptides for which receptors have been characterized in the bee genome, and whose essential roles turns them into the equivalent of a honey bee wanting system (dopamine) and NPY-like system (sNPF).
We have studied the impact of these molecules on feeding and foraging decisions and further aim at characterizing their role in central taste processing and salience.
Mechanisms of Olfactory Learning and Memory
Olfactory cognitionis also a main priority in our team. Using the fact that harnessed bees can be trained to associate an odorant with a reward of sucrose solution, we explore modifications of neural activity at key sites of the olfactory circuit as a consequence of associative learning. We use calcium imaging techniques to determine whether changes in activity depend on the complexity (elemental vs. non-elemental) of the learning task and on the specific relationship between stimuli to be learned (e.g. trace vs. delay conditioning) and the relationship between these changes and the time post acquisition.
A guiding hypothesis of our team is that mushroom bodies, which are prominent paired, central-brain structures, play an essential role for mastering higher-order cognitive discriminations. We target specific neurotransmitter pathways (GABAergic, cholinergic) in order to silence mushroom body function to determine the implication of these structures and pathways in complex problem solving. In addition, we determine candidate-gene upregulation and downregulation in the mushroom bodies as a consequence of different learning forms and processes leading to the formation of different memory phases. This allows conceiving interference strategies against the pathways recruited by these processes to demonstrate their necessity and sufficiency for the cognitive processes under study.
