What type of neurotransmitter action is characterized by slowing a neuron's firing speed?

The correct answer is characterized by inhibitory neurotransmitter action, which serves to reduce the likelihood of a neuron firing, effectively slowing its firing speed. Inhibitory neurotransmitters achieve this by binding to receptors on the postsynaptic neuron, leading to hyperpolarization of the neuron's membrane. This hyperpolarization makes it more difficult for the neuron to reach the threshold required for action potential generation, thereby inhibiting its overall activity.

In contrast, excitatory neurotransmitters increase the likelihood of firing by depolarizing the neuron and bringing it closer to the threshold for action potentials. Antagonistic action refers to substances that block or dampen the effects of neurotransmitters rather than directly slowing neuron firing. Synergistic refers to the interaction of two or more substances that produce a combined effect greater than their individual effects, which is not specifically related to slowing neuron firing. Understanding these distinctions helps clarify the role of inhibitory neurotransmitters in regulating neural activity.