NSC 201 Exam 4 A) PKA B) robo C) ephrins D) glucocorticoids E) BDNF F) CREB 1 G) TrkA H) laminin I) BMP J) phosphatases K) chordin Match the following with the terms above (2 pts. each). 1) During neural induction both noggin and chordin block the signaling activity of this molecule in the ectoderm 2) During both long-term sensitization and late-phase LTP this enzyme phosphorylates CREB1 to stimulate gene expression ________ 3) Nerve growth factor binds to this receptor to promote neuron survival ____________ 4) This class of molecules expressed within the optic tectum contributes to topographic organization in the retinotectal projection______ 5) This molecule triggers the differentiation of neural crest cells into adrenal chromaffin cells______ 6) This transcriptional regulator is implicated in both long-term sensitization and latephase LTP______. 7) Integrins expressed on the axon growth cone interact with this protein to promote contact-mediated adhesion ____________ 8) This member of the neurotrophin family essential to the survival of some neuronal populations______ 9) This receptor interacts with slit to guide axons away from the midline of the spinal cord after crossing. _______ 10) This class of enzyme is activated to induce long-term depression ________ For each statement circle True, False, or the correct response (2 pts. each) 1) Dorsal root ganglion cells are among the cell types derived from the neural crest. T/F 2) Sensitization of the gill withdrawal reflex in Aplysia is associated with decreased Ca++ influx into the sensory neuron’s terminal. T/F 3) Inducing long-term depression in the hippocampus requires NMDA receptor activation. T/F 4) The hippocampus is required for motor skill learning as evidenced by H.M.’s deficits in the mirror drawing test. T/F 5) Habituation in Aplysia is associated with a shorter/longer opening time for Ca++ channels in the sensory presynaptic terminal. 6). If the two optic nerves were always stimulated simultaneously during development the number of binocular cells in visual cortex would increase/decrease. 7) Blocking protein synthesis would slow down/speed up naturally-occurring cell death 8) Reducing neural activity equally in the two eyes during development would severely disrupt the segregation of ocular dominance columns. T/F 9) In the cerebral cortex, cells in the deeper layers are born before/after those in the upper layers. 10) The patient H.M would be expected to perform badly on a delayed match to sample task. T/F 11) Inducing long-term potentiation is made easier by depolarizing/hyperpolarizing the postsynaptic cell during synaptic activation 12) In general, smaller interneurons are born before large projection neurons. T/F 13) During short-term sensitization in Aplysia, broadening of the action potential is the result of phosphorylating Ca+ channels in the presynaptic terminal. T/F 14) Closing of the critical period in visual cortex is correlated with an increase/decrease in perineuronal nets. 15) Early-phase long-term potentiation can be induced even when protein synthesis is blocked. T/F 16) BMP signaling is critical for differentiation of the dorsal/ventral neural tube. 17) Blocking NMDA receptors in the developing visual cortex would lessen the effects of early monocular deprivation T/F Multiple choice (3 pts. each) 1) Long-term depression in the mammalian hippocampus differs from long-term potentiation in that LTD involves a) a smaller increase in postsynaptic Ca++ levels b) the activation of NMDA receptors c) the phosphorylation of AMPA receptors d) production of a retrograde messenger 2) Sensitization can be produced in the gill withdrawal circuit of Aplysia by a) applying serotonin directly to the sensory neuron b) injecting cAMP into the sensory neuron c) injecting the activated PKA catalytic subunit into the sensory neuron d) a and c e) all of the above 3) Which of the following best relates to the timecourse of short-term sensitization in Aplysia a) how long cAMP remains elevated b) how long CREB 1 is activated c) how long calmodulin is activated d) all of the above 4) Which of the following would cause ectodermal cells to differentiation into neural cells a) treatment with BMP b) dissociating the cells from one another c) removing them from the blastula before gastrulation d) all of the above 5) During classical conditioning in Aplysia coincidence between the CS and UCS is important because both these stimuli act to influence the activity of a) adenyl cyclase b) CaMKII c) NMDA receptors d) both a and c e) all of the above Fill in the blanks (3 pts. each) 1) Remembering the good times from one’s past is an example of ______________ memory. 2) This gas may serve as a retrograde messenger important for increasing neurotransmitter release following long-term potentiation _____________________ 3) These finger like protrusions of the growth cone contain actin filaments that aid in directing growing axons __________________________ 4) Named after an important video game character, secretion of this molecule from the notochord is important in directing the initial differentiation of cells in the ventral portion of the spinal cord __________________ 5) This molecule serves as both a chemorepellent and chemoattractant for axon guidance in the spinal cord_________ 6) One of the genes expressed to promote long-term sensitization codes for the protein ubiquitin hydrolase. On what enzyme does this protein act to prolong sensitization? ____________________ Answer the following questions 1) If ectodermal cells are isolated before gastrulation and grown in culture they will develop as epidermis when grown in a clump, yet develop as neurons when dissociated from each other. Why the difference? (4 pts) 2) In early phase LTP activation of CaMKII leads to three distinct changes that increase synaptic strength. Name two of them (4 pts) a) b) 3) In no more than two sentences (or a picture) describe the first experimental observation that identified the dorsal lip of the blastopore as an “organizer” region. (4 pts)
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