Draw an AP tracing against time. Describe the phases. Be sure to include a description
of all the components (ion channels) responsible for these phases, and also be sure to
appropriately label the graph (phases and axis labels) - ✔️✔️*Draw the AP graph and
label
1) resting state: Cell more negative inside, higher concentration of K+ inside, Na+
outside. This si the cell during the absecene of an AP.The Na+ and K+ channels are
closed.
2) Depolarization:A stimulus opens some sodium channels. Na+ flows through
depolarizing the membrane. If the depolarization reaches the threshold it causes an AP
3) Rising phase of the AP: Depolarization opens most Na+ v channels, K+ channels
remain closed, Na+ influx makes the inside of the membrane more positive with respect
to the outside
4)Falling phase: most Na+ channels become inactivated, most K+ channels open
causing K+ outflow, making the inside of the cell negative again
5) Undershoot: The Na+ channels are closed,but some K+ channels still open. As these
K+ channels close the NA+ becomes unblocked (still closed, and the membrane returns
to its resting state
1) Resting state repeated
provide context for your answer. - ✔️✔️SSRI's increase the amount of synaptic 5-HT
available for binding on the the 5HT-1a receptors by blocking reuptake. Initially this
causes more anxiety as the SSRI acts on the 5HT receptors. These presynaptic
receptors form an inhibitory feedback loop. In the presence of increased 5HT, there is a
decrease in the firing rate of these serotanergic neurons. These cells ultimately correct
themselves tho, to eventually maintain their baseline firing rate. They achieve this by
eliminating the amount of receptors on the presynaptic cell. These then return to
baseline firing in conjunction with the increased amount of 5HT at the synapses and the
post-synaptic cells are now able to receive appropriate firing and 5HT, therefore
reducing overall anxiety. This nuerocellular process explains the delayed initial efficacy
of SSRI treatment of anxiety.
Sodium channels on the axon involved in the action potential can open - ✔️✔️All of the
above
-in response to ligand binding
- in response to changes in voltage at the membrane
- in response to metabotropic reception activation
, The Central Dogma states - ✔️✔️Genes on DNA are translated to a protein folded to
there tertiary structure with chaperone proteins
The outward appearance of an organism, resulting from the genotype plus the
environment is referred to as the - ✔️✔️Phenotype
An SNP is - ✔️✔️All of the above...
-A single nucleotide polymorphism
-Useful in a linkage study
- may or may not be the cause of a disease
What process the occurs during meosis that allows to identify the relative location of
genes or polymorphisms on a chromosomes? - ✔️✔️Recombination
The resting potential of a neuron is generated/ maintained primarily by the - ✔️✔️the
sodium potassium pump
Voltage gated sodium channels - ✔️✔️open quickly with depolarization and then
inactivate
Which ion, when an ion channel specific to it has been opened, will move against its
electrical gradient? - ✔️✔️Mg++
Voltage gated potassium channels are responsible for - ✔️✔️repolarizing the
membrane during an action potential
Which ion is more concentrated on the intracellular side of the membrane? -
✔️✔️potassium
Describe the triplastic effect of SSRI when used to treat anxiety. Beside to describe the
receptor systems involved, and how they are related to anxiety in a general sense to \
If an ion channel specific to it were opened, in which direction would calcium flow? -
✔️✔️From the outside to the inside of the cell
What brain regions are most involved in the CS-US association in auditory fear
conditioning ? - ✔️✔️Lateral amgydala
Which ion is most related to neurotransmitter release - ✔️✔️Calcium
Which receptor is closely related to anxiety? - ✔️✔️the 5HT-1a receptor
Activation of the 5HT-1a receptor with a serotonin agonist has what effect on anxiety ? -
✔️✔️It increases it