What causes the action potential for the release of TRH?

Answer 1

The action potential for the release of thyrotropin-releasing hormone (TRH) is primarily triggered by depolarization of the neuron, which occurs when excitatory neurotransmitters bind to receptors on the hypothalamic neurons. This depolarization causes voltage-gated sodium channels to open, leading to an influx of sodium ions and further depolarization. Once the membrane potential reaches a threshold, an action potential is generated, propagating along the axon and ultimately resulting in the exocytosis of TRH from the nerve terminals into the portal circulation.