N-type calcium channel

[[File:Synapse diag1.svg|thumb|270px|Neuron A (transmitting) to neuron B (receiving)1. Mitochondrion

2. Synaptic vesicle with neurotransmitters

3. Autoreceptor

4. Synapse with neurotransmitter released (serotonin)

5. Postsynaptic receptors activated by neuro-transmitter (induction of a postsynaptic potential)

6. Calcium channel

7. Exocytosis of a vesicle

8. Recaptured neurotransmitter]]

The N-type calcium channel is a type of is_associated_with::voltage-dependent calcium channel. As with other sub-types of voltage-gated calcium channel, the α1 subunit forms the pore through which calcium enters the cell and determines most of the channel's properties. The α1 subunit is also known as the calcium channel, voltage-dependent, N type, alpha 1B subunit (CACNA1B) or Cav2.2 which in humans is encoded by the CACNA1B is_associated_with::gene.

Clinical significance
Mutations in CACNA1B are associated to Myoclonus-Dystonia syndrome.

Structure
In addition to the α1 subunit, the following subunits are present in the N-type calcium channel:
 * α2δ – is_associated_with::CACNA2D1, is_associated_with::CACNA2D2
 * β1 – is_associated_with::CACNB1
 * β3 – is_associated_with::CACNB3
 * β4 – is_associated_with::CACNB4

Function
N-type ('N' for "Neural-Type" ) calcium channels are found primarily at presynaptic terminals and are involved in is_associated_with::neurotransmission. Strong depolarization by an action potential causes these channels to open and allow influx of Ca2+, initiating vesicle fusion and release of stored neurotransmitter. N-type channels are blocked by ω-conotoxin.

Therapeutic Potential
Blockade of the N-type calcium channel is a potential therapeutic strategy for the treatment of is_associated_with::alcoholism. Blockade of N-type calcium channels in sensory neurons has therapeutic potential for the treatment of certain types of pain, particularly neuropathic pain. The peptide N-type calcium channel blocker is_associated_with::ziconotide is given intrathecally for intractable pain.

Blockers

 * ω-Conotoxins
 * is_associated_with::Ziconotide
 * is_associated_with::Caroverine
 * is_associated_with::Cilnidipine
 * NP078585
 * is_associated_with::TROX-1
 * is_associated_with::Gabapentin
 * is_associated_with::Levetiracetam
 * is_associated_with::Lamotrigine