355 Midterm 1
An inhibitory postsynaptic potential (IPSP) makes the postsynaptic neuron:
Less likley to fire an action potential
Diffusion of ions across the neuronal membrane is driven by:
Concentration gradients
Action potentials typically propagate along axons in which direction?
Unidirectionally, away from the soma.
What is a neuron's charge at resting potential?
-65mV
Hoe do metabotropic receptors differ from ionotropic receptions in terms of their effect on the postsynaptic neuron?
They initiate a series of biochemical reactions that can have diverse effects.
During an action potential, what follows the depolarization phase?
Repolarization
What is the Nernst equation used for?
Calculation the equilibrium potential for an ion.
How does the patch-clam method contribute to our understanding of action potentials?
By allowing the study of ionic currents through individual ion channels.
How do glial cells contribute to brain function?
They nourish and support the neuron.
In chemical synaptic transmission, what is the synaptic cleft?
The space between the presynaptic and postsynaptic membranes.
Where is an action potential intiated in the neuron?
In the axon hillock
During the falling phase of an action potential, which ionic movement predominates?
Efflux (output) of K+
How are neurotransmitters typically classified (3)?
usually classified by their chemical structure. i.e: amino acids, amines, peptides
G-protein Coupled Receptors in synaptic transmisson are known for what?
Initiating a series of biochemical reactions inside the cell.
At rest, the permeability of potassium across the neuronal membrane is (how many) more times greater than that of sodium?
40
What can electrical current across a membrane be generated by?
Applying an electrical field to charged ions.
At the neuromuscular junction, the neurotransmitter acetylcholine (ACh) is released form the presynaptic neuron into the synpatic cleft. What is the immediate effect on the postsynaptic muscle cell?
Depolarization
During the rising phase of an action potenetial, what is happening to the membrane potential?
It rapidly becomes more positively charged.
How do ion pumps contribute to the resting membrane potential?
By transporting ions against their concentration gradients using ATP.
What is axon transport essential for?
Moving materials between the soma and axon terminals