Question

A drug is designed to stimulate the voltage gated calcium channel at the neuronal synapse. What effect on neuronal transmission would you expect to see and why?

Answer 1

In neurons voltage gated calcium channels act as a mediator, a primary mediator which induces the influx of calcium ions via depolarization.

Multiple gene encoding results alpha 1 subunit's of calcium channel along with different varieties of it's subtypes. Which coassembles with a variety of ancillary calcium channel subunit's.

The above process allows it's calcium gated channel subtypes to full fill it's specialized role of neuronal calcium channels and at particulat subcellular loci.

They play a critical role in brain function and dysfunctionality in it leads to a diversity of neurological disorder such as, Migraine, Epilepsy, Pain etc. And so, these channel have a pharmacological importance for it's treatment.

These channels comprises of two major forms known to be as High Voltage Activated channel (HVA) and Low Voltage Activated channel (LVA).

The former channel opens in response to depolarization of membranes at large value.

Whereas, the later gets activated via small change in voltage near to resting potential phase of neuron respectively.

Therefore, there are subunit's of calcium channel subtypes determined as alpha1, alpha2, beta, gamma and delta. And calcium channel subtypes get determined by CaV1, CaV2, &CaV3. All of which have major subunit family of CaValpha1

This CaValpha1 is the key determinant of calcium channel subtypes. Subtype CaV1 encodes for three different L-type (termed as, CaV1.2, CaV1.3& CaV1.4) neuronal channel with specific skeletal muscle isoform (CaV1.4). These channels have characteristics of slow voltage dependent gating channels and are sensitive towards antagonist and agonist like DHP (Dihydropyridine).