Beat-locked cytosolic and mitochondrial ATP transients in SA node myocytes sort into high-gain, low-gain, or consumption-dominant modes aligned with superior–inferior vascular–mitochondrial gradients. This energetic hierarchy lets high-gain cells set fast rates, while low-gain/dip cells stabilize slow rhythms, broadening operating range but capping maximal bandwidth.

Within islets of Langerhans, gap junctions synchronize pulsatile [Ca²⁺] and insulin release. Subpopulations of insulin-producing β-cells that show unique dynamics can drive synchronized [Ca²⁺] and insulin release, and their loss in diabetes may drive islet dysfunction. Levitt et al. investigate how loss of gap junctions under diabetogenic environments and their protection influence these subpopulations.

Hoover Browne et al. report that deleting the P-zone domains A164–167 from titin in a novel mouse model reveals their critical role in muscle function and thick filament structure, including maintaining titin’s α and β conformations.

Cholesterol in cell membranes plays a key role in controlling how pain-sensing neurons respond. Our study shows that distinct cholesterol pools—OMD-associated and freely accessible cholesterol—differently influence HCN ion channels, which regulate nerve excitability. Changes in these pools after nerve injury alter pacemaker channel behavior, offering insights into pain mechanisms and potential treatments.

He et al. demonstrate that ion channels from photoreceptors in the retina are very sensitive to photodynamic modification mediated by singlet oxygen, ¹O₂, the molecular oxygen in electronically excited states. This study provides essential insights into the underlying mechanism of ¹O₂-mediated protein modification.

A neuronal nicotinic acetylcholine receptor from Xenopus tropicalis frogs possesses exquisite sensitivity to acetylcholine due to a single amino acid substitution in the α4 M3 domain possibly produced by RNA editing.

Navs exhibit high Li⁺ selectivity similar to Na⁺. We present the first prokaryotic Nav mutant that conducts Li⁺ with approximately twice the efficiency of Na⁺. Electrophysiological and crystallographic analyses suggest atomic determinants that facilitate Li⁺ permeation through the ion pore.