completely understood, however, it is suggested that this interaction causes Ca2+ to block the pore of the channel. Another form of chemical modulation is through the response of the channel to acidification (decrease of intracellular pH). It has been found that intracellular acidification causes a change in the C-terminal domain of connexins which then reduces the channel activity. Protein Phosphorylation – protein phosphorylation regulates the communication between channels in multiple ways by controlling: connexin trafficking from the Golgi Apparatus, accumulation of connexons to certain areas, and degradation of unnecessary channels. The process of these actions is very complex but involvement of protein phosphorylation is known. Humoral – humoral modulation of gap junction communication is done through many biomolecules such as neurotransmitters, growth factors, and various bioactive compounds. Neurotransmitters such as epinephrine and norepinephrine work in neuronal gap-junctions causing propagation of action potentials down neurons. These types of gap-junctions with this type of modulation are often found in neurons in cardiac tissue and vertebrate retina. Overall functions Connexons play an imperative role in behavior and neurophysiology. Many of the details surrounding their pathological functions remain unknown as research has only begun recently. In the central nervous system (CNS), connexons play a major role in conditions such as epilepsy, ischemia, inflammation, and neurodegeneration. The molecular mechanism as to how connexons play a role in the conditions listed above has yet to be fully understood and is under further research. Along with their key role in the CNS, connexons are crucial in the functioning of cardiac tissues. The direct connection allows for quick and synchronized firing of neurons in the heart which explains the ability for the heart to beat quickly and change its rate in response to certain stimuli. Connexons also play an essential role in cell development. Specifically, their role in neurogenesis dealing with brain development as well as brain repair during certain diseases/pathologies and also assisting in both cell division as well as cell proliferation. The mechanism by which connexons aid in these processes is still being researched however, it is currently understood that this mechanism involves purinergic signaling (form of extracellular signaling mediated by purine nucleotides and nucleosides such as adenosine and ATP) and permeability to ATP. Other important roles of connexons are glucose sensing and signal transduction. Connexons cause changes in extracellular glucose concentrations affecting feeding/satiety behavior, sleep-wake cycles, and energy use. Further studies indicate that there is