Neuromodulation enables temperature robustness and coupling between fast and slow oscillator circuits in Cancer borealis

Acute temperature changes can disrupt neuronal activity and coordination with severe consequences for animal behavior and survival. Nonetheless, two rhythmic neuronal circuits in the crustacean stomatogastric ganglion (STG) and their coordination are maintained across a broad temperature range. However, it remains unclear how this temperature robustness is achieved. Here, we dissociate temperature effects on the rhythm generating circuits from those of upstream ganglia. We demonstrate that heat-activated factors extrinsic to the rhythm generators are essential to the slow gastric mill rhythm's temperature robustness and contribute to the temperature response of the fast pyloric rhythm. The gastric mill rhythm crashed when only the STG circuits were heated. It could be restored when upstream ganglia were heated in addition, and the activity of the peptidergic modulatory projection neuron (MCN1) increased. Correspondingly, MCN1's neuropeptide transmitter stabilized the rhythm and maintained it over a broad temperature range. Extrinsic neuromodulation is thus essential for the oscillatory circuits in the STG and enables neural circuits to maintain function in temperature-compromised conditions. In contrast, integer coupling between pyloric and gastric mill rhythms was independent of whether extrinsic inputs and STG pattern generators were temperature-matched or not, demonstrating that the temperature robustness of the coupling is enabled by properties intrinsic to the rhythm generators. However, at near-crash temperature, integer coupling was maintained only in some animals but was absent in others. This was true despite regular rhythmic activity in all animals, supporting that degenerate circuit properties result in idiosyncratic responses to environ-mental challenges.

Broad temperature range ferrielectric liquid crystal with subwavelength helix pitch

The ferrielectric liquid crystal (FerriLC) phase with the helix pitch po of about 100 nm was revealed in a broad temperature range from -3°C to + 35°C in a mixture containing an achiral smectic-C (SmC) biphenylpyrimidine and two non-mesogenic chiral diesters of 4,4”-terphenyl dicarboxylic acid.

Nanowires self-assemble into β-MnO2 nanospheres to form crosslinking 3D hierarchical porous networks: with template-free fabrication and good supercapacitive performance over a broad temperature range

Template-free fabrication of nanowires self-assembling into nanospheres and crosslinking into 3D hierarchical porous β-MnO2 networks with good supercapacitive performance over a broad temperature range.