How does a neurotransmitter affect the postsynaptic cell?

How does a neurotransmitter affect the postsynaptic cell?

The binding of neurotransmitters, either directly or indirectly, causes ion channels in the postsynaptic membrane to open or close (Figure 7.1). Typically, the resulting ion fluxes change the membrane potential of the postsynaptic cell, thus mediating the transfer of information across the synapse.

What affects the postsynaptic neuron?

The effect is proportional to the average amount of neurotransmitter present and the number of receptors. Thus, the effect of the presynaptic neuron on the postsynaptic neuron is proportional to the product of the presynaptic firing rate and the number of receptors present.

What effect will a neurotransmitter have on the postsynaptic membrane quizlet?

What effect will a neurotransmitter have on the postsynaptic membrane? It may produce a depolarization or a hyperpolarization. Describe characteristics of receptors at the synapses.

What is the effect of the binding of neurotransmitters to their receptors on the postsynaptic cell membrane?

Stimulation of excitatory receptors by neurotransmitter binding causes depolarization of the postsynaptic plasma membrane, promoting generation of an action potential. Conversely, stimulation of inhibitory receptors causes hyperpolarization of the postsynaptic membrane, repressing generation of an action potential.

Why is the postsynaptic membrane important?

The postsynaptic membrane contains specific ACh receptors (AChR), concentrated opposite the active zones. These are one of the best-characterized ionic channels. Their opening allows ions to flow following the specific binding of ACh. It is the two α subunits of the AChR that contain the ACh binding sites.

Are postsynaptic potentials resting potentials?

Postsynaptic potentials are changes in membrane potential that move the cell away from its resting state. For our purposes, postsynaptic potentials are measured in the dendrites and cell bodies.

What type of channel in the postsynaptic membrane binds neurotransmitter?

The neurotransmitter diffuses across the synaptic cleft and binds to ligand-gated ion channels in the postsynaptic membrane, resulting in a localized depolarization or hyperpolarization of the postsynaptic neuron.

What happens to neurotransmitters after reuptake?

Reuptake: the whole neurotransmitter molecule is taken back into the axon terminal that released it. This is a common way the action of norepinephrine, dopamine and serotonin is stopped…these neurotransmitters are removed from the synaptic cleft so they cannot bind to receptors.

What happens to serotonin after reuptake?

Our data show that after acute reuptake inhibition, less serotonin is available for release during closely repeated stimulations and that concurrent synthesis and reuptake inhibition exacerbates this depletion.

What are two functions of neurotransmitters at the postsynaptic membrane?

After release into the synaptic cleft, neurotransmitters interact with receptor proteins on the membrane of the postsynaptic cell, causing ionic channels on the membrane to either open or close. When these channels open, depolarization occurs, resulting in the initiation of another action potential.

How are neurotransmitters released in the postsynaptic neuron?

Binding of the neurotransmitters to their receptors open up these channels. This changes the ion permeability of the cell membrane. The synapse is unidirectional i.e. from pre-synaptic neuron to the postsynaptic neuron as the former releases the neurotransmitters and the later has receptors on its cell surface membrane.

How is spatial summation related to neurotransmission?

Spatial summation is the process in which simultaneous action potential in several presynaptic neurons releases a large number of neurotransmitters into the synaptic cleft. The magnitude of depolarization generated in the post-synaptic neuron reaches the threshold potential and an action potential is generated.

How are neurotransmitters removed from the synaptic cleft?

Removal of neurotransmitters from the synaptic cleft occurs by enzymatic degradation, re-uptake into the presynaptic cell, or diffusion. Chemical synapses allow a single postsynaptic cell to amplify, modify, and compute excitatory and inhibitory signals received from multiple presynaptic neurons.

When does the post synaptic membrane become depolarized?

Temporal summation is the process in which the presynaptic neuron generates action potentials in very close succession. The post-synaptic membrane becomes depolarized due to the first action potential of the pre-synaptic neuron.