Question

1. When a new college student moves into his dorm room he is woken up every night by the train whistles from the nearby train tracks. After a few weeks he realizes that he sleeps through the night every night. What happened to this student?

A. Habituation

B. Plasticity

C. long-term sensitization

D. stimulus

E. Short-term sensitization

2. A student interested in the molecular mechanism of learning would look for change in a synapse undergoing long-term potentiation?

A. decrease in calcium currents in the postsynaptic cell

B. decreased depolarizations measured in the postsynaptic cell

C. Increase in presynaptic neurotransmitter release

D. increase in numbers of NMDA receptors in the postsynaptic membrane

E. Increase in numbers of AMPA receptors in the postsynaptic membrane

3. Which molecule phosphoyylates AMPA receptors to increase sodium conductance?

A. CAM

B. Na+

C. NMDA

D. Ca2+

E. CaMII

Answer 1

1. Habituation is a form of non-associative learning ( stimulus and behavior are not paired) in which a natural response to a stimulus decreases after repeated or prolonged exposure to that stimulus.

Behavioral plasticity is the change in an organism's behavior that is caused due to the exposure to a stimuli, such as changing environmental conditions.  

Sensitization is a form of nonassociative learning that involves enhancing the response to a weak stimulus that occurs after the presentation of a strong stimulus. Two types of sensitization are long term and short term sensitization.  Short-term sensitization lasts seconds to minutes and involves the modification of neuronal membrane properties and synaptic efficacy. Long-term sensitization lasts from days to weeks.

A stimulus is an object or event that brings about a sensory or behavioral response in an organism. A stimulus behavior. It is a change in the energy (e.g., light or sound) which is registered by our senses (e.g., vision, hearing, taste, etc.) and constitutes the basis for perception.

Thus, the answer for this question is option (A) Habituation

2. Long-Term Potentiation or LTP is the ability of brain cells to retain the frequency of senTPding signals to other brain cells. LTP can be induced either by strong tetanic stimulation of a single pathway to a synapse, or cooperatively through the weaker stimulation of many pathways. When stimulus is applied weakly to one pathway into a synapse, it produces insufficient postsynaptic depolarization to induce LTP. This means that the postsynaptic depolarization measured are decreased in the cel. Thus the answer is option (B) decreased depolarizations measured in the postsynaptic cell

3. In a regulated pathway,  AMPA receptors are trafficked to the synapse in an activity-dependent manner which is stimulated by NMDA receptor activation. CaMKII-mediated phosphorylation of GluA1 S831 increases the channel conductance and regulates LTP. Therefore the answer is option (E) CAMII