** Homoaromaticity ( exceptional: a cyclic homolog with ring expansion: e. g. homotropylium, bishomotropylium but the conjugated pi electron cloud remain very similar to the pair of circular donuts above and below the carbong ring and retain the similar electron configuration.

** cyclohexane-a 6-carbon aliphatic cyclic hydrocarbon sometimes used as a non-polar solvent

** hereditary disorders ( e. g. congenital neutropenia, cyclic neutropenia )

** Cyclic ( mathematics ) shows other terms in mathematics beginning with cyclic or cycle

** victorin-a chlorinated cyclic pentapeptide made by the pathogenic fungus Cochliobolus victoriae.

** a primary cyclic group, which is a p-primary, cyclic group.

** Cyclic nucleotide-gated channels: This family of channels is characterized by activation due to the binding of intracellular cAMP or cGMP, with specificity varying by member.

** Cation channels of sperm: This small family of channels, normally referred to as Catsper channels, is related to the two-pore channels and distantly related to TRP channels.

** Inward-rectifier potassium channels: These channels allow potassium to flow into the cell in an inwardly rectifying manner, i. e., potassium flows effectively into, but not out of, the cell.

** Calcium-activated potassium channels: This family of channels is, for the most part, activated by intracellular Ca < sup > 2 +</ sup > and contains 8 members.

** Two-pore-domain potassium channels: This family of 15 members form what is known as leak channels, and they follow Goldman-Hodgkin-Katz ( open ) rectification.

** Voltage-gated potassium channels e. g., Kvs, Kirs etc.

** Calcium-activated potassium channels e. g., BKCa or MaxiK, SK, etc.

** Inward-rectifier potassium channels

** Two-pore-domain potassium channels: This family of 15 members form what is known as leak channels, and they follow Goldman-Hodgkin-Katz ( open ) rectification.

** voltage-gated sodium channels NaVs

** epithelial sodium channels ( ENaC )

** Voltage-gated proton channels

** Most Transient receptor potential channels

** Freeview digital free satellite with a dozen SD channels, with SD feeds of the terrestrial HD freeview channels.

* Hyperpolarization-activated cyclic nucleotide-gated channels: The opening of these channels is due to hyperpolarization rather than the depolarization required for other cyclic nucleotide-gated channels.

Following activation of adenylate cyclase, the resulting cAMP acts as a second messenger by interacting with and regulating other proteins such as protein kinase A and cyclic nucleotide-gated ion channels.

* Cyclic nucleotide-gated channels: This superfamily of channels contains two families: the cyclic nucleotide-gated ( CNG ) channels and the hyperpolarization-activated, cyclic nucleotide-gated ( HCN ) channels.

This in turn causes the Ga-subunit of the protein to activate a phosphodiesterase ( PDE6 ), which degrades cGMP, resulting in the closing of Na + cyclic nucleotide-gated ion channels ( CNGs ).

There are at least four genetic causes of congenital ACHM, two of which involve cyclic nucleotide-gated ion channels ( ACHM2 / ACHM3 ), a third involves the cone photoreceptor transducin ( GNAT2, ACHM4 ), and the last remains unknown.

Known genetic causes of this are mutations in the cone cell cyclic nucleotide-gated ion channels CNGA3 ( ACHM2 ) and CNGB3 ( ACHM3 ) as well as the cone cell transducin, GNAT2 ( ACHM4 ).

cGMP is particularly important in visual perception as its level controls the opening of cyclic nucleotide-gated ion channels ( CNGs ).

* Cyclic nucleotide-gated ion channel an ion channel gated by cyclic nuclotide like cAMP

# The net concentration of intracellular cGMP is reduced ( due to its conversion to 5 ' GMP via PDE ), resulting in the closure of cyclic nucleotide-gated Na < sup >+</ sup > ion channels located in the photoreceptor outer segment membrane.

This emergent property of the neuron is thought to comprise, the expression of the aforementioned proteins as well as various voltage-sensitive channels including the hyperpolarization-activated, cyclic nucleotide-gated ( HCN ) channel and the rapidly activating and inactivating transient potassium channel ( IK < sub > A </ sub >).

The cAMP opens cyclic nucleotide-gated ion channels which allow calcium and sodium ions to enter into the cell, depolarizing the olfactory receptor neuron and beginning an action potential which carries the information to the brain.

Cyclic nucleotide-gated ion channels or CNG channels are ion channels that function in response to the binding of cyclic nucleotides.

An example of the role of cyclic nucleotide-gated ion channels in sea urchin sperm chemotaxis.

Illustration of a cyclic nucleotide-gated ion channel with a cAMP binding domain.

When the cyclic nucleotide-gated ion channels are closed, the cytoplasmic ends of the S6 helices are in close proximity to each other.

In the cells from an inner medullary collecting duct, CNG channels exhibit cation selectivity unit conductance, calcium permeability, and pharmacology very similar to cyclic nucleotide-gated ion channels.

These channels are also sensitive to the cyclic nucleotides cAMP and cGMP, which alter the voltage sensitivity of the channel ’ s opening.

* HCN channel, a type of hyperpolarization-activated cyclic nucleotide gated channels

In the dark, cells have a relatively high concentration of cyclic guanosine 3 '- 5 ' monophosphate ( cGMP ), which opens ion channels ( largely sodium channels, though calcium can enter through these channels as well ).