Neuronal signalling 1

Play an AI-generated podcast conversation about this lesson

What type of synapse involves a direct contact between cells allowing synchronization, such as in the contraction of the heart?

Electrical synapse (correct)

Chemical synapse

Neuronal synapse

Signal synapse

Which neurotransmitter is commonly released from axon terminals in a chemical synapse?

Serotonin

Acetylcholine (correct)

Dopamine

GABA

What occurs when voltage-gated Ca2+ channels open in a presynaptic neuron?

Release of neurotransmitters via endocytosis (correct)

Depolarization of the postsynaptic membrane

Inhibition of action potential propagation

Closure of sodium channels in the postsynaptic neuron

What is the main function of an excitatory postsynaptic potential (EPSP) in a neuronal system?

Depolarize the postsynaptic neuron towards threshold Signup and view all the answers

In what scenario does temporal summation occur in a synapse?

Continuous firing of EPSPs to reach threshold Signup and view all the answers

Which ion, when binding to ion channels on a postsynaptic neuron, is responsible for causing hyperpolarization?

Chloride (Cl-) Signup and view all the answers

What is the function of an inhibitory postsynaptic potential (IPSP) in a neural circuit?

Hyperpolarize the postsynaptic neuron Signup and view all the answers

During spatial summation, what happens when different EPSPs add up together at a synapse?

They lead to membrane depolarization Signup and view all the answers

What happens when only a single ion channel opens during an excitatory postsynaptic potential?

Threshold value to trigger an action potential isn't reached. Signup and view all the answers

Explain the process involved when voltage-gated Ca2+ channels open in a presynaptic neuron.

Voltage-gated Ca2+ channels open in the presynaptic neuron, allowing Ca2+ to enter. This causes the release of vesicles containing neurotransmitters via exocytosis. Signup and view all the answers

Define an excitatory postsynaptic potential (EPSP) and explain its significance in neuronal communication.

An EPSP is when a single ion channel opens, but it's not enough to reach the threshold potential to trigger an action potential. It serves to depolarize the membrane slightly, bringing it closer to the threshold for firing. Signup and view all the answers

Describe the process of temporal summation at a synapse and how it influences neuronal signaling.

Temporal summation involves constant firing of EPSPs to reach the threshold value for triggering an action potential. It allows for integration of multiple signals over time to determine if an action potential will be generated. Signup and view all the answers

Explain the concept of spatial summation in a synapse and its role in neural communication.

Spatial summation occurs when different EPSPs add up together to reach the threshold value for triggering an action potential. It involves integrating signals from multiple synapses simultaneously to determine if firing will occur. Signup and view all the answers

What is the mechanism of an inhibitory postsynaptic potential (IPSP) and how does it affect neuronal excitability?

An IPSP is when a single ion channel, such as Cl-, opens, making the membrane more negative and less likely to trigger an action potential. It serves to hyperpolarize the membrane, increasing the threshold for firing. Signup and view all the answers