Calcium channels
Main function
Voltage-gated calcium channels open when cells become electrically active and allow calcium to enter. In nerve cells, this calcium triggers the release of neurotransmitters and helps control how easily neurons fire. Other calcium channel subtypes regulate pain pathways, muscle contraction, heart activity and rhythmic electrical signalling. Their exact function depends strongly on the calcium channel subtype involved.
Main body locations
Positive and negative describe interaction direction, not whether an effect is good or bad. Activating a target can have unwanted effects, while reducing or blocking it can sometimes have beneficial effects.
Increased activity
Increased calcium channel activity can increase neurotransmitter release and make some nerves more active. In pain-sensing nerves this can strengthen the transmission of pain signals. In muscle and heart cells, calcium entry supports normal contraction and electrical activity. Excessive activity of particular calcium channel subtypes could lead to abnormal pain signalling and excessive neuronal activity.
No linked substances yet.
Reduced or blocked activity
Reduced calcium channel activity can decrease neurotransmitter release and make some nerve cells less excitable, potentially reducing pain signalling and excessive repetitive nerve activity. Several medicines use this general system to treat pain, seizures or cardiovascular conditions, although different drugs target different calcium channel subtypes.