Lecture on Synaptic Integration

These flashcards cover key concepts related to synaptic integration and graded potentials discussed in the lecture.

What is the primary learning outcome of this lecture on synaptic integration?

To explain the role of synaptic integration in neuronal function.

What are the properties of graded potentials?

Graded potentials are graded, decremental, can be depolarizing (excitatory) or hyperpolarizing (inhibitory), and can summate.

What is an excitatory postsynaptic potential (EPSP)?

A depolarizing graded potential that brings the neuron closer to threshold to fire an action potential.

What is an inhibitory postsynaptic potential (IPSP)?

A hyperpolarizing graded potential that moves the neuron away from threshold, making it less likely to fire an action potential.

What is temporal summation?

The stimulation of one input in rapid succession to bring a neuron to threshold.

What is spatial summation?

The simultaneous stimulation of multiple inputs to bring a neuron to threshold.

What role does the initial segment or axon hillock play in neuronal firing?

It decides whether an action potential will be fired based on whether the threshold of -55 millivolts is reached.

How do inhibitory synapses affect synaptic integration?

They decrease the likelihood of reaching threshold by hyperpolarizing the neuron and decreasing neurotransmitter release.

What is presynaptic inhibition?

A form of inhibition where an inhibitory input decreases neurotransmitter release from a presynaptic terminal.

What are axoaxonic synapses?

Synapses that synapse onto the presynaptic terminal of another neuron, typically inhibiting neurotransmitter release.

What is the physiological relevance of synaptic integration in neurons?

It is crucial for determining whether a neuron reaches threshold to fire an action potential by summation of excitatory and inhibitory inputs.

What is the threshold voltage for an action potential to be fired?

-55 millivolts.