A toxin produced by an aquatic cell blocks voltage gated calcium channels. With your knowledge of the nervous system, propose a mechanism for why...

The primary cells of the nervous system are neurons. Neurons need to communicate with each other in order to send information, in the form of electrical signals, throughout the body. Some neurons simply send those signals directly into other neurons, but the majority of them do not. Instead, they release chemicals into the (very small) space in between one neuron and another. You can think of this like writing on a post-it note and handing...

The primary cells of the nervous system are neurons. Neurons need to communicate with each other in order to send information, in the form of electrical signals, throughout the body. Some neurons simply send those signals directly into other neurons, but the majority of them do not. Instead, they release chemicals into the (very small) space in between one neuron and another. You can think of this like writing on a post-it note and handing it to the person next to you. The messages (chemicals) that the neurons release are called neurotransmitters, and voltage-gated calcium channels are critical to their function.

The first step in communication is the arrival of an electrical signal (called an action potential) which triggers the calcium channels to open. This influx of calcium signals vesicles (small "bubbles" inside the cell, filled with neurotransmitters) to go to the edge of the cell, fuse with the membrane, and release their neurotransmitters.

If the calcium channels are blocked, this will interfere with the functioning of the neurotransmitters. If being used as an analgesic, the subject will be unable to feel pain, because the cells receiving the "pain" signal will be unable to communicate that message to any other neuron. The individual receptor cell still knows what's going on, but it has basically been muted.