What is the effect of excitatory synapses on target cells?

Excitatory synapses play a crucial role in neuronal communication by increasing the likelihood that the target cell will generate an action potential. When an excitatory neurotransmitter binds to its receptor on the postsynaptic neuron, it typically leads to the opening of ion channels that allow positively charged ions, such as sodium (Na+), to enter the cell. This influx of positive ions depolarizes the postsynaptic membrane, moving the membrane potential closer to the threshold needed to trigger an action potential.

The consequent depolarization of the postsynaptic neuron increases its excitability, making it more likely to fire in response to subsequent stimuli. This mechanism is essential for processes such as learning, memory, and overall neural communication. Thus, the effect of excitatory synapses is characterized by their ability to facilitate the firing of target cells, enhancing their response to potential signals. This is distinct from inhibitory synapses, which typically function to reduce the likelihood of action potentials by hyperpolarizing the neuron or stabilizing its membrane potential.