Cryptochrome-dependent magnetoreception in heteropteran insect continues even after 24 hours in darkness

Sensitivity to magnetic fields is dependent on the intensity and color of light in several animal species. The of light-dependent magnetoreception working model points to Cryptochrome (Cry) as a protein able to cooperate with its cofactor flavin, which possibly becomes a magnetically susceptible pair upon excitation by light. What type of Cry is involved as well as what pair of magnetosensitive radicals are responsible is still elusive. Therefore, we developed a conditioning assay for the firebug (the firebug) Pyrrhocoris apterus, an insect species that possesses only the mammalian Cryptochrome (Cry II). Here, using the engineered Cry II null mutant, we show that: i) vertebrate-like Cry II is an essential component of the magnetoreception response, and ii) magnetic conditioning continues even after 25 hours in darkness. The light-dependent and dark-persisting magnetoreception based on Cry II may inspire new perspectives in magnetoreception and Cryptochrome research.

Changes in Cerebello-motor Connectivity during Procedural Learning by Actual Execution and Observation

The cerebellum is involved in motor learning of new procedures both during actual execution of a motor task and during observational training. These processes are thought to depend on the activity of a neural network that involves the lateral cerebellum and primary motor cortex (M1). In this study, we used a twin-coil TMS technique to investigate whether execution and observation of a visuomotor procedural learning task is related to modulation of cerebello-motor connectivity. We observed that, at rest, a magnetic conditioning pulse applied over the lateral cerebellum reduced the motor-evoked potentials obtained by stimulating the contralateral M1, indicating activation of a cerebello-motor connection. Furthermore, during procedural learning, cerebellar stimulation resulted in selective facilitation, not inhibition, of contralateral M1 excitability. The effects were evident when motor learning was obtained by actual execution of the task or by observation, but they disappeared if procedural learning had already been acquired by previous observational training. These results indicate that changes in cerebello-motor connectivity occur in relation to specific phases of procedural learning, demonstrating a complex pattern of excitatory and inhibitory drives modulated across time.