Speaker
Description
ABSTRACT:
The mechanisms underlying magnetoreception remain unresolved, although several theoretical models are considered plausible. In the honeybee (Apis mellifera), an especially suitable model system due to the scale and complexity of its navigational behavior, two mechanisms are potentially involved: the Radical Pair Model (RPM) and the Magnetite-Based Model (MBM). These mechanisms are not necessarily mutually exclusive but may act in a complementary manner, with the MBM providing spatial mapping information and the RPM functioning as a fast compass system.
Experimental evidence in honeybees indicates sensitivity to magnetic field polarity as well as the presence of ferromagnetic particles in the antennae and abdomen, supporting the plausibility of the MBM. However, receptor structures functionally linked to magnetite particles have never been conclusively identified. By contrast, while the RPM has been supported in several insect species, it has not yet been directly tested in Apis mellifera. Importantly, a suitable quantum-biological substrate for RPM-based magnetoreception has been identified in the honeybee, namely the photoreceptor cryptochrome (CRY).
Targeted behavioral assays based on classical conditioning and navigation tasks will be used to verify honeybee sensitivity to controlled magnetic field variations and to guide the selection of stimulation paradigms for neural recordings. These experiments will probe sensitivity to magnetic field inclination, a key prediction of the Radical Pair Mechanism (RPM), and explore responses to polarity changes relevant to the Magnetite-Based Mechanism (MBM).
Because direct functional data on magnetoreception are currently lacking in Apis mellifera, the project will employ two-photon calcium imaging to investigate neural responses to controlled magnetic field stimulation. Two-photon microscopy enables cellular-resolution recordings of neural activity during magnetic field manipulations. Imaging will be performed in the anterior optic tubercle (AOTu) in combination with blue-light stimulation to test for magnetically modulated activity consistent with RPM-based mechanisms. To avoid optical contamination of the calcium imaging signal, blue-light stimulation will be synchronized with the flyback phase of the two-photon scanning, preventing background light from being detected by the highly sensitive photodetectors of the microscope. In addition, functional imaging will be explored in candidate regions associated with MBM pathways, including the antennal lobes (AL).
If behavioral and functional evidence converges in support of the RPM, the project will proceed to a causal test of cryptochrome involvement through somatic genome editing to generate a CRY knockout. In parallel, to obtain a more comprehensive view of geomagnetic information processing in the honeybee brain, the feasibility of generating a transgenic line expressing GCaMP under the synapsin promoter (GCaMP::Synapsin) will be explored using CRISPR/Cas9, with the aim of improving construct integration precision and line viability.
BIOGRAPHY:
My academic training spans cognitive science and neurobiology, with a strong focus on the neural mechanisms underlying behavior and information processing. Over the years, I have combined behavioral paradigms with experimental neurobiology, gaining hands-on experience in calcium imaging and immunohistochemistry in insect and vertebrate animal models. My primary research interest lies in in vivo imaging of neural activity in both vertebrate and invertebrate systems. I am particularly interested in directly monitoring neural dynamics to better understand how information is encoded, processed, and integrated within biological systems. As part of a multidisciplinary neurophysics environment, my PhD research focuses on magnetoreception, a still underexplored sensory modality used by many animals and insects for spatial navigation. I investigate how the physical principles governing geomagnetic field interact with neural circuit dynamics. This work allows me to integrate systems neuroscience, sensory biology, and biophysical approaches. In parallel, I maintain a strong interest in genetics and molecular biology, particularly in strategies that enable the mechanistic dissection of neural circuits and hold translational potential for neuroscience and neuroimaging.