Impact of continuous positive airway pressure on cognitive functions in adult patients with obstructive sleep apnea: A systematic review and meta-analysis.

Background: Obstructive sleep apnea (OSA) is associated with the impairment of a range of cognitive functions. Whether treatment with continuous positive airway pressure (CPAP) improves these cognitive functions is still a matter of debate.

Methods: We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) that included OSA patients (apnea hypopnea index, AHI >10/h), naive to CPAP treatment, with a cognitive assessment before and after CPAP initiation.

Ankyrin G Membrane Partners Drive the Establishment and Maintenance of the Axon Initial Segment.

The axon initial segment (AIS) is a highly specialized neuronal compartment that plays a key role in neuronal development and excitability. It concentrates multiple membrane proteins such as ion channels and cell adhesion molecules (CAMs) that are recruited to the AIS by the scaffold protein ankyrin G (ankG). The crucial function of ankG in the anchoring of AIS membrane components is well established, but a reciprocal role of membrane partners in ankG targeting and stabilization remained elusive.

Nanoscale Architecture of the Axon Initial Segment Reveals an Organized and Robust Scaffold.

The axon initial segment (AIS), located within the first 30 μm of the axon, has two essential roles in generating action potentials and maintaining axonal identity. AIS assembly depends on a ßIV-spectrin/ankyrin G scaffold, but its macromolecular arrangement is not well understood. Here, we quantitatively determined the AIS nanoscale architecture by using stochastic optical reconstruction microscopy (STORM).

A dynamic formin-dependent deep F-actin network in axons.

Although actin at neuronal growth cones is well-studied, much less is known about actin organization and dynamics along axon shafts and presynaptic boutons. Using probes that selectively label filamentous-actin (F-actin), we found focal "actin hotspots" along axons-spaced ∼3-4 µm apart-where actin undergoes continuous assembly/disassembly. These foci are a nidus for vigorous actin polymerization, generating long filaments spurting bidirectionally along axons-a phenomenon we call "actin trails.

CK2-regulated schwannomin-interacting protein IQCJ-SCHIP-1 association with AnkG contributes to the maintenance of the axon initial segment.

The axon initial segment (AIS) plays a central role in electrogenesis and in the maintenance of neuronal polarity. Its molecular organization is dependent on the scaffolding protein ankyrin (Ank) G and is regulated by kinases. For example, the phosphorylation of voltage-gated sodium channels by the protein kinase CK2 regulates their interaction with AnkG and, consequently, their accumulation at the AIS.