Hyperpolarization-activated (pacemaker) channels are dually gated by negative voltage and intracellular cAMP. Kinetics of native cardiac f-channels are not compatible with HH gating, and require closed/open multistate models. We verified that members of the HCN channel family (mHCN1, hHCN2, hHCN4) also have properties not complying with HH gating, such as sigmoidal activation and deactivation, ...

van Welie I, du Lac S. Bidirectional control of BK channel open probability by CAMKII and PKC in medial vestibular nucleus neurons. J Neurophysiol 105: 1651–1659, 2011. First published February 9, 2011; doi:10.1152/jn.00058.2011.—Large conductance K (BK) channels are a key determinant of neuronal excitability. Medial vestibular nucleus (MVN) neurons regulate eye movements to ensure image stabil...

Current magnitude in Kv2.1 potassium channels is modulated by external [K+]. In contrast to behavior expected from the change in electrochemical driving force, outward current through Kv2.1 channels becomes larger when extracellular [K+] is increased within the physiological range. The mechanism that underlies this unusual property involves the opening of Kv2.1 channels into one of two differen...

Skeletal and cardiac dihydropyridine receptors function both as voltage-dependent L-type calcium channels (L-channels) and as critical proteins that trigger calcium release from the sarcoplasmic reticulum in muscle. In spite of these similarities, skeletal L-channels exhibit a markedly slower activation rate than cardiac L-channels. We investigated the mechanisms underlying this difference by c...

Voltage clamp measurements on myelinated nerve fibers show that tetrodotoxin, saxitoxin, and DDT specifically affect the sodium channels of the membrane. Tetrodotoxin and saxitoxin render the sodium channels impermeable to Na ions and to Li ions and probably prevent the opening of individual sodium channels when one toxin molecule binds to a channel. The apparent dissociation constant of the in...

What are they? P2X channels are a family of cell-membrane cation channels which open within milliseconds of binding ATP. They are distinct from the other family of ATP receptors, the G-proteincoupled P2Y receptors, and also from other transmitter-gated ion channels. P2X channels are the third major family of mammalian transmitter-gated ion channels (Figure 1); they are similar in topology to am...

Activity of the bacterial mechanosensitive channels of small conductance MscS/MscK of E. coli was investigated under high hydrostatic pressure (HHP) using the "flying-patch" patch-clamp technique. The channels were gated by negative pipette voltage and their open probability was measured at HHP of 0.1 to 80 MPa. The channel open probability decreased with increasing HHP. When the osmolyte methy...

P2X receptors are trimeric cation channels that open in response to binding of extracellular ATP. Each subunit contains a large extracellular ligand binding domain and two flanking transmembrane (TM) helices that form the pore, but the extent of gating motions of the TM helices is unclear. We probed these motions using ivermectin (IVM), a macrocyclic lactone that stabilizes the open state of P2...

Spatial Coupling A General Phenomenon • General one-dimensional systems • General BMS channels Threshold Saturation and Universality • Multi-user communications and ISI channels Multi-access channels Noisy Slepian-Wolf Finite state channels Many more... • Problems beyond Communications Compressive sensing K-SAT Practical Aspects and Open Questions • Universality • Windowed decoding • Rate loss ...