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What Hyperpolarizing membrane potential occurs in the postsynaptic membrane of a synapse?
Wiki User
∙ 14y ago
Hyperpolarization means that the membrane potential becames more negative than the resting potential. This means that it is more difficult for an action potential to be triggered at the postsynaptic membrane. This occurs at inhibitory synapses.
Hyperpolarization can be achieved by increasing the permeability of the membrane to potassium or chloride ions. If potassium permeability is increased more potassium ions will leave the cell, down their concentration gradient; if chloride permeability increases chloride ions will enter the cell down their concentration gradient. Both movements will make the inside of the cell more negative ie they will cause hyperpolarization.
Wiki User
∙ 14y ago
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What type of membrane potential is generated at the synapse on the postsynaptic membrane?
It can be an excitatory postsynaptic potential (EPSP) or an inhibitory postsynaptic potential (IPSP), depending on the synapse. The EPSP depolarizes the membrane, while the IPSP hyperpolarizes it.
When the second excitory postsynaptic potential arrives at a single synapse before the effect of the first has disappeared what occurs?
Temporal summation occurs at a single synapse that is activated by a second excitory postsynaptic potential occurring in rapid succession before the first has disappeared.
What is the presynaptic knob ca2?
Your question isn't very clear.... Presynaptic knob is the neurone before the synapse. Postsynaptic knob is the neurone after the synapse. Calcium ions diffuse into the presynaptic knob down their concentration gradient when an impulse arrives at the presynaptic knob. This causes the vesicles to move towards the presynaptic membrane and fuse with it. This releases the neurotransmitter (e.g. Ach). The Ach diffuses down their concentration gradient in the synaptic cleft then binds with receptors on the post synaptic membrane. This binding causes the Na+ ion channels to open, and the influx of Na+ ions causes depolarisation, and a new action potential in the postsynaptic knob. Then the acetate and choline diffuses back into the presynaptic membrane and is recombined using ATP.
What is the difference between action potentials and synaptic potentials?
A synaptic potential exists at the INPUT of a neuron (dendrite), and an action potential occurs at the OUTPUT of a neuron (axon). (from OldGuy)(from Ilantoren:) A synaptic potential is the result of many excitatory post synaptic potentials (epsp) each one caused by the synaptic vesicles released by the pre-synaptic terminus. If there are enough of these epsp then the responses will summate and depolarize the post-synaptic membrane at the axon hillock enough to fire an action potential.
When nerve impulses from several presynaptic neurons stimulate a single postsynaptic neuron at the same time it is called?
chemical synapse
What type of membrane potential is generated at the synapse on the postsynaptic membrane?
It can be an excitatory postsynaptic potential (EPSP) or an inhibitory postsynaptic potential (IPSP), depending on the synapse. The EPSP depolarizes the membrane, while the IPSP hyperpolarizes it.
Are graded potentials the same as local potentials?
Postsynaptic potentials are changes in the membrane potential of the postsynaptic terminal of a chemical synapse. Graded potentials are changes in membrane potential that vary in size, as opposed to being all-or-none, and are not postsynaptic potentials.
The activity of acetylcholine in a synapse is terminated by?
Its degradation by a hydrolytic enzyme on the postsynaptic membrane.
A postsynaptic potential is a graded potential that is the result of a neurotransmitter released into the synapse between two neurons?
true
What is the name of the tiny gap the neurotransmitter has to diffuse across to reach the membrane of the postsynaptic neuron?
the synapse
When the second excitory postsynaptic potential arrives at a single synapse before the effect of the first has disappeared what occurs?
Temporal summation occurs at a single synapse that is activated by a second excitory postsynaptic potential occurring in rapid succession before the first has disappeared.
What is the relationship between the action potential and the synapse?
A synapse and an action potential have a flip-flopping cause and effect relationship, in that an action potential in a presynaptic neuron initiates a release of neurotransmitters across a synapse, which can then subsequently potentially trigger an action potential in the axon of the postsynaptic neuron, which would then cause release of neurotransmitters across a following synapse.
Is a postsynaptic potential a graded potential that is the result if a neurotransmitter released into the synapse between two neurons?
Yes it is true that graded potential can be called postsynaptic potentials. When a sensory neuron is excited by some form of energy, the resulting graded potential is called generator potential.
The condition that produces inhibition at a synapse is called what?
Neurotransmitters diffuse across the synaptic cleft (a very short distance) and bind to receptor proteins on the postsynaptic membrane. Excitatory neurotransmitters cause sodium ions to move through receptor proteins depolarizing the membrane. Inhibitory neurotransmitters do not depolarize the postsynaptic membrane. Thus, the condition that would produce inhibition at synapse is called HYPERPOLARIZATION.
What is the term for the cell that receives a signal at a synapse?
The cell receiving the signal at the synapse is called the postsynaptic neuron.
What term refers to a neurotransmitter?
are endogenous chemicals which relay, amplify, and modulate signals between a neuron and another cell.[1] Neurotransmitters are packaged into synaptic vesicles that cluster beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to receptors in the membrane on the postsynaptic side of the synapse. Release of neurotransmitters usually follows arrival of an action potential at the synapse, but may follow graded electrical potentials. Low level "baseline" release also occurs without electrical stimulation.
What is the difference between an excitatory synapse and an inhibitory synapse?
Synapses are junctions that allow a neuron to electrically or chemically transmit a signal to another cell. Synapses can either be excitatory or inhibitory. Inhibitory synapses decrease the likelihood of the firing action potential of a cell while excitatory synapses increase its likelihood. Excitatory synapses cause a positive action potential in neurons and cells. For example, in the neurotransmitter Acetylcholine (Ach), its binding to receptors opens up sodium channels and allows an influx of Na+ ions and reduces membrane potential which is referred to as Excitatory Postsynaptic potential(EPSP). An action potential is generated when the polarization of the postsynaptic membrane reaches threshold. ACh acts on nicotinic receptors which can be found at the neuromuscular junction of skeletal muscles, the parasympathetic nervous system, and the brain. It also acts on muscarinic receptors found at neuromuscular junctions of the smooth muscles, glands, and the sympathetic nervous system. Inhibitory synapses, on the other hand, cause the neurotransmitters in the postsynaptic membrane to depolarize. An example is the neurotransmitter Gamma Aminobutyric Acid (GABA). The binding of GABA to receptors increases the flow of chloride (CI-) ions in the postsynaptic cells raising its membrane potential and inhibiting it. The binding of GABA to receptors activates a second messenger opening potassium channels.
