What type of synapse causes the target cell to become less likely to fire an action potential?

Inhibitory synapses are critical in regulating neuronal activity by making the target cell less likely to fire an action potential. When an inhibitory synapse is activated, it typically results in the release of neurotransmitters such as gamma-aminobutyric acid (GABA) or glycine. These neurotransmitters bind to receptors on the postsynaptic neuron, leading to an influx of negatively charged ions (such as chloride) or an efflux of positively charged ions (such as potassium). This process hyperpolarizes the neuron, increasing the negative voltage inside the cell and moving the neuron further away from the threshold needed to trigger an action potential.

This mechanism is essential for maintaining balance in the nervous system by preventing excessive excitation, which could lead to conditions such as seizures. In contrast, excitatory synapses increase the likelihood of an action potential by depolarizing the neuron. While neural synapses refer to general connections between neurons and electrical synapses involve direct cytoplasmic connections between cells, neither of these categories specifically emphasizes the reduction of action potential firing likelihood as the inhibitory synapses do.