the receptors on the postsynaptic membrane
Neurotransmitters are chemical messengers that transmit signals and information from the presynaptic neuron to the postsynaptic neuron at the synapse. They bind to receptors on the postsynaptic neuron, leading to changes in its membrane potential and triggering a new signal to be passed along the neural pathway. Some common neurotransmitters include acetylcholine, dopamine, serotonin, and glutamate.
GABA binds to GABA receptors on the postsynaptic neuron, leading to an influx of negatively charged chloride ions into the neuron. This hyperpolarizes the neuron, making it less likely to generate an action potential and thereby inhibiting its activity.
Excitatory postsynaptic potentials (EPSPs) are produced when neurotransmitters bind to excitatory receptors on the postsynaptic membrane, causing a depolarization of the neuron. This depolarization results in the opening of ion channels that allow positively charged ions, such as sodium and calcium, to enter the neuron, further depolarizing it. The cumulative effect of EPSPs from multiple synapses can reach the threshold for action potential initiation.
When neurotransmitters communicate an inhibitory message to the postsynaptic neuron:
a neuron from the axon terminal of which an electrical impulse is transmitted across a synaptic cleft to the cell body or one or more dendrites of a postsynaptic neuron by the release of a chemical neurotransmitter.
A postsynaptic potential occurs when neurotransmitters released from the presynaptic neuron bind to receptors on the postsynaptic neuron, causing a change in its membrane potential. This change can be either depolarizing (excitatory) or hyperpolarizing (inhibitory), influencing the likelihood of the postsynaptic neuron firing an action potential.
The tiny gap that the neurotransmitter has to diffuse across to reach the membrane of the postsynaptic neuron is called the synaptic cleft. It separates the axon terminal of the presynaptic neuron from the dendrite of the postsynaptic neuron.
Excitatory neurotransmitter
When two or more presynaptic neurons synapse with a single postsynaptic neuron in the central nervous system (CNS), it forms a convergent pathway. This allows for integration of multiple inputs onto a single neuron, influencing the postsynaptic neuron's response.
Synaptic events refer to the processes involved in communication between neurons at synapses. These events include neurotransmitter release from the presynaptic neuron, binding of neurotransmitters to receptors on the postsynaptic neuron, and subsequent changes in the postsynaptic neuron's membrane potential. This can lead to excitation or inhibition of the postsynaptic neuron based on the type of neurotransmitter and receptors involved.
A neurotransmitter that allows sodium ions to leak into a postsynaptic neuron causes excitatory postsynaptic potentials. The neurotransmitter that is not synthesized in advance and packaged into synaptic vesicles is nitric oxide.