Exam 2 Clicker Questions Flashcards
Which stressor hormone is most likely involved in mediating behavioral responses to stress by acting on the brain?
a) Epinephrine
b) CORT
b) CORT (Corticosterone in rodents and Cortisol in humans) because it can cross the BBB and bind to its receptors in the brain, affecting behavior!
Which of the following is important for initiating release of the stress hormone, CORT?
a) The ventromedial nucleus of the hypothalamus
b) The paraventricular nucleus of the hypothalamus
c) The ventromedial nucleus of the thalamus
d) The paraventricular nucleus of the thalamus
b) the paraventricular nucleus of the hypothalamus - The PVN secretes corticotropin-releasing hormone (CRH) and vasopressin into the hypophyseal portal system, which then act on the anterior pituitary gland to secrete adrenocorticotropic hormone (ACTH). ACTH then stimulates the adrenal cortex to produce and release CORT into the bloodstream.
How is the HPA axis able to shut off after being activated?
a) The HPA axis stops activity when the stressor is removed
b) Glucose stores are depleted after an immediate stressor so the HPA axis shuts off
c) CORT binds to GRs on the hypothalamus and pituitary to shut off the HPA axis
d) The HPA axis receives input from the parasympathetic nervous system, which tells it to shut off
c) CORT binds to GRs on the hypothalamus and pituitary to shut off the HPA axis - The hypothalamic-pituitary-adrenal (HPA) axis can shut off its activity through a negative feedback loop where CORT (cortisol in humans, corticosterone in rodents) binds to glucocorticoid receptors (GRs) in the hypothalamus and the pituitary gland. This binding inhibits the release of corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH), which in turn reduces the release of CORT from the adrenal glands, thereby dampening the HPA axis activity.
Which of the following is a consequence of GPCR activation?
a) Gene expression is altered
b) Intracellular proteins are altered
c) Downstream ion channels are altered
d) First messenger signal is amplified
e) All of the above
e - all of the above - Activation of G protein-coupled receptors (GPCRs) can lead to a variety of cellular responses including altered gene expression, changes in the activity of intracellular proteins, modulation of downstream ion channels, and amplification of the first messenger signal. GPCRs activate intracellular signaling cascades that can have multiple effects on cellular functions.
***Using electrophysiology, what do you think would be a good measure of LTP?
a) There is greater postsynaptic depolarization in response to the same electrical stimulation
b) There is greater postsynaptic hyperpolarization in response to the same electrical stimulation
c) There is a greater excitatory post-synaptic potential (EPSP) to the same electrical stimulation
d) A and C
e) B and C
c) There is a greater excitatory post-synaptic potential (EPSP) to the same electrical stimulation
What is the result of increased AMPA receptors into the post-synaptic cell?
a) The postsynaptic cell has more intracellular signaling cascades initiated
b) The postsynaptic cell becomes insensitive to glutamate
c) The postsynaptic cell is more permeable to Ca2+ ions
d) The postsynaptic cell is more permeable to Na+ ions
d) The postsynaptic cell is more permeable to Na+ ions
A strong stimulus results in long-term potentiation because:
a) There is more depolarization of the post-synaptic cell, allowing more Na+ to flow in
b) There is more depolarization of the post-synaptic cell, allowing Ca2+ to flow in
c) There is more hyperpolarization of the post-synaptic cell, allowing more K+ to flow out
d) The presynaptic cell releases more glutamate, activating mGluRs resulting in intracellular signaling cascades
b) There is more depolarization of the post-synaptic cell, allowing Ca2+ to flow in.
Long-term potentiation (LTP) is typically associated with the activation of NMDA receptors, which are voltage-dependent and require both glutamate binding and post-synaptic depolarization to remove the Mg2+ ion that blocks the channel. Once this block is removed, Ca2+ can flow into the post-synaptic cell, which triggers a cascade of intracellular events that lead to synaptic strengthening and the molecular changes associated with LTP.
After you administer a strong stimulus, LTP is induced. This is measured by the fact that a weak stimulus can now induce a strong effect (strong synaptic activity). What is the underlying mechanism behind this?
a) There are more NMDA receptors inserted into the postsynaptic cell
b) There are more AMPA receptors inserted into the postsynaptic cell
c) The AMPA receptors have a lower threshold for activation
d) The NMDA receptors have a lower threshold for activation
b) There are more AMPA receptors inserted into the postsynaptic cell.
One of the key changes during LTP is the activity-dependent increase in the number of AMPA receptors in the postsynaptic membrane, which enhances the postsynaptic cell’s response to glutamate released by a subsequent weak stimulus. This increased number of AMPA receptors allows for more sodium ions (Na+) to enter the postsynaptic neuron upon glutamate binding, thus amplifying the postsynaptic response.
What contributes to the persistence of LTP?
a) Ca2+ influx initiates protein synthesis
b) AMPA receptors are stabilized into the PSD
c) Na+ influx initiates protein synthesis
d) A and B
e) B and C
d) A and B
The influx of Ca2+ during LTP is crucial for activating intracellular signaling pathways that lead to protein synthesis, including the synthesis of new AMPA receptors and their insertion and stabilization at the synaptic site. This stabilization of AMPA receptors at the PSD is important for the maintenance of the strengthened synaptic response characteristic of LTP.
What are the 4 main steps in the scientific process?
1) Observation -observe a behavior, manipulate variables
2) Replication - repeat your findings within the same lab
3) Interpretation - make conclusions about your data and distribute your findings
4) Reproducibility - other labs can repeat your findings
What determines which cells are a target for a particular systemic hormone?
a) The target cell expresses the enzymes to produce the hormone
b) The target cell expresses the proteins for the hormone receptor
c) The target cell contains the DNA for the hormone receptor
d) Astrological sign and vibes of the target cell
e) B and C
b) The target cell expresses the proteins for the hormone receptor
Hormones exert their effects on cells by binding to specific receptors expressed on the surface or inside of target cells. The presence of these receptors makes a cell responsive to a particular hormone.
How are hormones able to reach their target cell?
a) Through the synaptic cleft between the presynaptic and postsynaptic cell
b) Through the bloodstream
c) Through diffuse axons have synapses on many different neurons
d) Through cerebrospinal fluid
b) Through the bloodstream
What is the difference between a releasing hormone and an effector hormone?
-a releasing hormone acts on endocrine cells to regulate the release of other hormones
-an effector hormone produces a regulatory effect on a cell or tissue to produce a physiological or psychological function
What type of hormone is being released from the posterior pituitary?
a) Neurohormones
b) Tropic hormones
c) Steroid hormones
d) A and B
a) Neurohormones.
The posterior pituitary gland releases neurohormones, which are hormones that are produced by neurosecretory cells and released into the blood following a neural signal. The main neurohormones released by the posterior pituitary are oxytocin and vasopressin (antidiuretic hormone, ADH)
Why do you think it’s functionally important for the magnocellular neurons and the parvocellular neurons to differ in cell body size?
a) The types of neurohormones they produce differ in size
b) They have different lengths in axons
c) They produce different quantities of hormone
d) They have different neuronal firing rates
c) They produce different quantities of hormone
Magnocellular neurons, which are larger, are involved in the production of larger quantities of oxytocin and vasopressin (neurohormones) and have axons that project to the posterior pituitary. The larger size of magnocellular neurons supports the higher volume of neurohormone production and transport needed for release into the bloodstream