Scientist that studied patients with hippocampal lesions and anterograde amnesia, providing insights to the neuroscience of memory
Who is Brenda Milner?
The probability of release of a synapse can be altered by changing the concentration of _____, with _____ probability synapses having a smaller releasable vesicle pool and a ____ PPR:
What is: Ca2+, low, large (above 1)
Describe the overall molecular pathway for ON bipolar cells in the light/dark. Is it the same for OFF bipolar cells?
What is:
Dark: In ON cells, which have metabotropic receptors, glutamate (present in the dark since photoreceptors depolarize in the dark) activates mGluR6, a GPCR, and this inhibits TRPM1 (ion channel).
Light: glutamate is not present, so TRPM1 is not inhibited, so the channel is open and the cell depolarizes
No - OFF bipolar cells have ionotropic receptors where glutamate helps open AMPA channels
Why is the speed of the pain and touch pathways different?
What is: The fibers responsible for pain (A-delta and C) are thinner in diameter and less myelinated (C fibers are not myelinated) than the fibers responsible for touch (A-beta)
Based on Ohm’s Law, how is current affected if resistance is increased and voltage is kept constant?
What is: current would decrease (V=IR)
Scientist that created the Reticular Theorem, and what does it state?
Who is Golgi?
The nervous system is comprised of a single continuous network.
What type of experiment produces each graph?
A)
B)
C)
D)
What is:
A) Extracellular, B) Patch clamp, C) Intracellular, D) Voltage clamp
What are the functions of the two major areas in the ventral stream of visual processing?
What is:
V4: shape and color perception
Area IT: processing of complex objects (e.g., faces)
A motorcycle accident causes a transection through the left half of a patient’s spinal cord, describe the specific pattern of sensory and motor loss that would occur.
What is:
Left: damaged tough and proprioception (these don’t cross until the medulla) and motor damage
Right: damaged pain/touch/itch (these paths cross immediately at the spinal cord)
How does the activation of the periaqueductal gray (PAG) region of the brain contribute to the analgesic effects of opioids?
What is: activation of the PAG region leads to the release of endorphins (norephinephring and endogenous opiods) from downstream brainstem structures, which suppress pain signals throughout the body
Increasing the extracellular concentration of Sodium would do what to the resting membrane potential:
What is: not much :/
A nerve cell has a resting membrane potential of -70mV and a threshold of -55mV. The reversal potential for one type of synapse on this neuron is -60mV and it allows the flow of cations. Is this synapse excitatory or inhibitory?
What is: Inhibitory
It will depolarize the cell but prevent it from reaching -55mV (threshold) since its reversal potential is more negative (-60mV). An excitatory synapse is one that will increase the likelihood of cell reaching the threshold
Name the two types of photoreceptors. How are they different?
What is: Rods and cones. Rods are more sensitive to light; cones are sensitive to different wavelengths of light. There are no rods in the fovea.
Which sensory receptors are fast adapting? What does this mean? What are the differences between the two fast adapting sensory receptors?
What is: Meissner and Pacinian. This means they are good for detecting changes in sensation and vibrations. Meissner corpuscles are small and respond best to light touch low frequency vibrations while Pacinian corpuscles are larger and respond best to pressure and high frequency vibrations.
Is the presence of Calcium necessary for induction, expression, and maintenance of LTP? Explain.
What is: No, calcium flowing through NMDA receptors is necessary to induce LTP, CaMKII activation is necessary for LTP expression, but gene expression and protein translation and long lasting CamKII activity are the main mechanisms for LTP maintenance.
The stage of the action potential where driving force for sodium is lowest
What is action potential peak?
What is the presynaptic series of signaling event types and what is responsible for each?
What is: Electrical (potential coming into terminal) → Chemical (VGCa+ channels open to let Ca+ into cell (important!!, Vince Young!!)) → Mechanical (protein conformational changes, SNARE binds vesicle to membrane so it’s ready to release, Ca+ binds to synaptotagmin which is attached to vesicle and will cause conformation change in other proteins that will allow vesicle to fuse with membrane) → Chemical (neurotransmitter release)
Location where orientation selectivity starts in the visual system
What are V1 cells? or What is the primary visual cortex?
Describe a key difference between the structure and role of intrafusal muscle fibers vs intrafusal muscle fibers.
What is: Intrafusal muscle fibers are within the muscle spindles; they are responsible for detecting changes in muscle length and change via sensory receptors with proprioceptive feedback. Extrafusal muscle fibers are responsible for generating force and movement - they contract in response to motor neuron stimulation and generate muscle movement.
The main excitatory neurotransmitter at the neuromuscular junction is:
The main excitatory neurotransmitter in the brain is:
The main inhibitory neurotransmitter in the brain is:
What is: acetylcholine, glutamate, GABA
Besides voltage gated potassium channel activation, this channel property is integral to the repolarization phase of the action potential
What is: sodium channel inactivation
What is the role of acetylcholine esterase and what happens when this protein is inhibited with things like Sarin (think of the synapse heavy with ACh use)?
What is: it breaks down acetylcholine at the synaptic cleft. With it inhibited, ACh will stay in synaptic clefts of NMJs → muscles continuously contracting and lose the ability to breathe (lethal)
Describe the retinal rhodopsin pathway when light is present
What is:
1. Light activates (bleaches) rhodopsin.
2. Transducin, the G-protein, is stimulated.
3. Phosphodiesterase (PDE), the effector enzyme, is activated.
4. PDE activity reduces the cGMP level.
5. cGMP-gated cation channels close, and the cell membrane hyperpolarizes
Neuronal mechanisms of increasing muscle force
What are increasing firing rate and recruiting additional motor units?
Technique in neuroscience that uses light to modulate electrical activity in neurons.
What is optogenetics?