In some cells, the hemichannel itself is active as a conduit between the cytoplasm and the extracellular space, allowing the transference of ions and small molecules lower than 1-2 KDa.

[5] In a single gap junction, connexons will assemble around an aqueous porous membrane, forming a hemi-channel that is composed of connexins.

Connexins are the smaller protein molecules that make up connexons and play a crucial part to the formation of gap junctions.

Since then, connexons have been increasingly detected forming channels in single membranes considerably broadening their functionality in cells and tissues.

In the central nervous system (CNS), connexons play a major role in conditions such as epilepsy, ischemia, inflammation, and neurodegeneration.

[1] Further studies indicate that there is an increase in glucose uptake mediated by connexons (whose mechanism is still not fully understood) and under times of high stress and inflammation.

Gap junctions are often present at nerve endings such as in cardiac muscle and are important in maintaining homeostasis in the liver and proper function of the kidneys.

[8] Cardiovascular disease and possibly type I and II diabetes, are each associated with a major protein connexin that makes up the gap junction.

In cardiovascular disease, Cx43 (connexin 43), a subunit of a connexon, is a general protein of the gap junction stimulating cardio myocyte muscle cells of intercalated discs facilitating synchronized beating of the heart.

In the occurrence of cardiovascular disease the Cx43 subunit begins to show signs of oxidative stress, the ability of the heart to counteract the buildup of harmful toxins due to age or diet leading to reduced vascular functions.

[8] Additionally, reduced Cx43 expression in vascular tissue, which plays a part in ventricular remolding and healing of wounds after a myocardial infarction, are present in structural heart disease.

[9] Overall, these changes in Cx43 expression and oxidant stress can lead to abnormalities in the coordinated beating of the heart, predisposing it to cardiac arrhythmias.

[4] Homeostasis in the liver and pancreatic organs are supported by an intricate system of cellular interactions called endocrine signaling.

Thus the purpose of the gap junction is to regulate the passage of ions, nutrients, metabolites, second messengers, and small biological molecules.

A deficiency of Cx36 adversely affects the ability of the gap junction to operate within these tissues leading a reduction in function and possible disease.