When a muscle fiber is held at a voltage of 0 mV at the neuromuscular end plate, acetylcholine no longer produces a current because:
- the acetylcholine receptor channels all close instantly at 0 mV.
- an influx of sodium is balanced by an equal efflux of potassium.
- the membrane conductance for each permeant ion is 0 at 0 mV.
- at 0 mV, the potassium ions lodge in the receptor channel and block the influx of sodium.
- the Nernst potentials for both sodium and potassium are 0 mV in muscle fibers.
Answer: 2
Biopsychology
- Kluver-Bucy syndrome is characterized by:
- Which of the following neurotransmitters has been identified as seminally involved in an organism's reward system and is often altered by drugs of abuse?
- Two brain structures not originally proposed by Paper as important to emotional experience and expression, but now known to be important, are the ____ and the _____.
- Which of the following brain structures have been identified as primary sites where neuronal activity is altered by drugs of abuse?
- Which of the following is a symptom of clinical depression?
- Ventral divisions of the basal ganglia receive excitatory inputs from the:
- In associative learning studies of monkey, dopaminergic neural activity in the ventral segmental area of subjects that had been successfully conditioned to a stimulus showed:
- Which of the following does not provide inputs to the amygdala?
- The "Duchenne smile":
- The most enigmatic aspect of emotional experience is:
- An inability to express emotion through modulation of speech is called:
- Which of the following brain substrates is not involved in non-volitional emotional expressions?
- Activation of the visceral component of the sympathetic nervous system as it relates to emotional processing:
- Which are the following statements about lateralization of emotional processing is true?
- A response to a ______ constitutes a conditioned fear response in the rat.
- Which of the following was not one of the findings of the Bard and Hess studies of emotion?
- Which of the following statements about the amygdala is false?
- The "vicarious states" of Damasio give mental representations contingencies that:
- Functional neuroimaging studies (by Drevets and Raichle) of subjects with unipolar depression have shown:
- Patient S.M., who suffered selective bilateral damage to the amygdala, exhibited:
- Which of the following is not part of the hippocampus?
- Which of the following statements about the plasticity of synapses in the mammalian CNS is false?
- In the context of neuropathological activity, the phenomenon of kindling refers to:
- Which of the following statements about long-term synaptic plasticity in Aplysia is false?
- Firing an action potential in an axon initially causes a 10 mV depolarization (EPSP) in a postsynaptic neuron, but after giving a certain stimulus to the axon, firing it causes an 8 mV depolarization, after each action potential. This phenomenon is called: