200812495 2014 2 11 26Weekly QA
2008-12495 권성연
2014년도 2학기 신경과학
제출일자 11월 26일
Weekly Q&A (25)
1. Outline the steps involved in the presynaptic release of neurotransmitter. Why would the closure of a potassium channel in the presynaptic axon terminal change the amount of Ca2︎ entering and change the amount of neurotransmitter released?
Serotonin(5-HT) receptor on the sensory axon terminals is a G-protein-coupled metabotropic receptor. Stimulation of this receptor leads to the production of intracellular second messengers, cAMP, which activates protein kinase A. This enzyme phosphorylates various proteins, among which a potassium channel. Since potassium channel is closed by phosphorylation, the presynaptic action potential is elongated, resulting in more Ca2 entry through voltage-gated calcium channels during the action potential. More quanta of neurotransmitter are released because of this series of action.
2. Rabbits can be classically conditioned to blink in response to a tone. This is accomplished by repeatedly pairing the tone with an air puff to the eye. Richard Thompson and his colleagues at
Stanford University have made the following observations: Learning fails to occur, and the memory is wiped out, if the cerebellum is surgically removed; the air puff activates cells in the inferior olive; the tone activates cerebellar mossy fibers. Using your knowledge of synaptic plasticity in the cerebellum, propose a mechanism for classical conditioning in the rabbit.
In this setting, the CS is a tone and the US is the air puff to the eye of a rabbit. In classical conditioning, the subject(rabbit) learns that the CS predicts the US. Here, the CS activates cerebellar mossy fibers, which synapses on cerebellar granule cells. Cerebellar granule cells give rise to axons that branch as a parallel fiber. The US activates cell in the inferior olive, which integrates information from muscle proprioceptor and projects its axons, climbing fibers, to the Purkinje cells. The convergence of parallel and climbing
2014년도 2학기 신경과학
제출일자 11월 26일
Weekly Q&A (25)
1. Outline the steps involved in the presynaptic release of neurotransmitter. Why would the closure of a potassium channel in the presynaptic axon terminal change the amount of Ca2︎ entering and change the amount of neurotransmitter released?
Serotonin(5-HT) receptor on the sensory axon terminals is a G-protein-coupled metabotropic receptor. Stimulation of this receptor leads to the production of intracellular second messengers, cAMP, which activates protein kinase A. This enzyme phosphorylates various proteins, among which a potassium channel. Since potassium channel is closed by phosphorylation, the presynaptic action potential is elongated, resulting in more Ca2 entry through voltage-gated calcium channels during the action potential. More quanta of neurotransmitter are released because of this series of action.
2. Rabbits can be classically conditioned to blink in response to a tone. This is accomplished by repeatedly pairing the tone with an air puff to the eye. Richard Thompson and his colleagues at
Stanford University have made the following observations: Learning fails to occur, and the memory is wiped out, if the cerebellum is surgically removed; the air puff activates cells in the inferior olive; the tone activates cerebellar mossy fibers. Using your knowledge of synaptic plasticity in the cerebellum, propose a mechanism for classical conditioning in the rabbit.
In this setting, the CS is a tone and the US is the air puff to the eye of a rabbit. In classical conditioning, the subject(rabbit) learns that the CS predicts the US. Here, the CS activates cerebellar mossy fibers, which synapses on cerebellar granule cells. Cerebellar granule cells give rise to axons that branch as a parallel fiber. The US activates cell in the inferior olive, which integrates information from muscle proprioceptor and projects its axons, climbing fibers, to the Purkinje cells. The convergence of parallel and climbing