Signaling Amongst Neurons

Question 1

seven processes in neurotransmitter action

Answer 1

• neurotransmitter molecules are synthesize from precursors under the influences of enzymes
• neurotransmitter molecules are stored in vesicles
• neurotransmitter molecules that leak from their vesicles are destroyed by enzymes
• action potentials cause vesicles to use with the presynaptic membrane and release their neurotransmitter molecules into the synapse
• released neurotransmitter molecules bind with auto receptors and inhibit subsequent neurotransmitter release
• released neurotransmitter molecules bind to postsynaptic receptors
• released neurotransmitter molecules re deactivated either by reuptake or enzymatic degradation

Question 2

effects of neurotransmitters

Answer 2

• bind to receptor sites on the postsynaptic membrane
• the binding process alters specific ionic permeability of the postsynaptic membrane at the receptor site, resulting in a local graded potential

Question 3

information can be transmitted between two neurons when:

Answer 3

• neurotransmission results in EPSPs and IPSPs in the receiving neurons dendrites
• if this does not happen no information can be transmitted between two neurons

Question 4

ionotropic receptor

Answer 4

• a receptor that contains a binding site for a neurotransmitter and an ion channel that opens when a molecule of the neurotransmitter attaches to the binding site

Question 5

metabotropic receptor

Answer 5

• a receptor that contains a binding site for a neurotransmitter which activates an enzyme that beings a series of events openings an ion channel elsewhere in the neurons’ membrane when a molecule of the neurotransmitter attaches to the binding site

Question 6

g protein

Answer 6

• a protein coupled to a metabotropic receptors conveys messages to other molecules when a ligand binds with and activates the receptor

Question 7

second messenger

Answer 7

a chemical produced when a G protein activates an enzyme
- carries a signal that results in the opening of the ion channel or causes other events to occur in the cell

Question 8

neurons code signals to create information

Answer 8

• done through integration of ESPSs and IPSPSs
• to save energy it owuld make sense for coding to be sparse
• neurons must code signals to creaste information in the neervous system

Question 9

dynamic range

Answer 9

• dynamic range of a neuron is limited by the neiron’s ability to create action potentials

Question 10

neural integration

Answer 10

• the process by which inhibitory postsynaptic potentials (IPSPs and excitatory postsynaptic potentials (EPSPs) summate and control the rate of firing of a neurons
• only within a given time frame and spatial area