Exam 2 - Prep Quizzes

Somatosensory information traveling along thalamocortical axons that enter the sensory cortex, primarily terminate on neurons that reside in cortical Layer ____?

4

Diagram questions: The number _[x]_ indicates the location of DRG sensory neuron bodies. The number _[x]_ indicates the location where proprioceptive information from the patients right quadriceps muscle ascends in the spinal cord. If you transplanted a Shh-coated bead onto site #18 early in spinal cord development, the type of neurons normally located at 13 might also be found at number [x] . The number _[x]_ indicates the location where pain sensing afferents from the patients left hand synapse in the spinal cord.

6: dorsal root ganglion 1: dorsal column 14 or 15: If Shh was put at posterior median sulcus, the type of neurons normally located at the ventral horn might also be found at the lateral or dorsal horn. 15 - posterier (dorsal) horn *complete with names

Cortical layer 4 neurons send axons that synapse onto Layer 2/3 pyramidal neurons and undergo plasticity during sensory learning. Which of the following pharmacological agents would be most effective at blocking long-term potentiation at this synapse.

APV (R-2-amino-5-phosphonopentanoate

What defect in the visual field would be a result of damage at #7

Add to cram ppt

What type of sensory afferent fiber exhibits the slowest conduction velocity?

C

What is the role of NMDA receptors in long-term potentiation (LTP) in the hippocampus?

Calcium entry through the NMDA receptors occurs only when the presynaptic and postsynaptic elements are active at the same time.

Which is required for long-term potentiation in the hippocampus?

De novo protein synthesis in CA1 excitatory neurons

What is the best explanation for the lack of synaptic depression during high frequency stimulation when the extracellular calcium concentration is significantly reduced?

Depletion of the pool of synaptic vesicles is reduced when calcium influx into the presynaptic space is decreased

The loss of embryonic BMP expression in the developing nervous system is most likely to cause which of the following problems?

Dorsal localization of normally ventral neuronal subtypes in the spinal cord

True or false: Axonal guidance is only regulated by diffusible cues.

False

Neurotrophic factors do NOT directly regulate .....?

GPCR activity Answers: d. GPCR activity a. the number of surviving neurons b. synapse formation c. axonal outgrowth

A patient has had an unfortunate car accident that resulted in spinal cord damage. Below the level of the belly button, the patient has difficulty sensing light touch on the right side and heat on the left side. Where is the most likely location of the spinal cord injury?

Hemisection of the right spinal cord at T10

Identify the correct order of steps in the anatomical circuit for mechanosensory informatio

In correct order: 1. First Order Neuron in DRG relays peripheral information into the spinal cord. 2. Afferents ascend and synapse on second order-neurons in the ipsilateral medulla. 3. Medullary afferents cross the midline, ascend, and synapse on third-order neurons in the contralateral thalamus. 4. Thalamic afferents synapse on neurons in the primary sensory cortex.

What is true about the neural crest?

It generates the neurons of the peripheral nervous system and the peripheral glia

Loss of which of the following secreted cues would have the largest effect on the survival of nociceptive sensory neurons during development?

NGF

Which of the following biochemical changes does NOT occur following light stimulation of a photoreceptor?

Opening of cGMP dependent cation channels

Which of these is NOT involved in neuronal outgrowth into the PNS?

Radial glia incorrect answers: Growth cones Lamellipodia Filopodia

Which cells provide the scaffolding for cell migration in the cerebral cortex and set the stage for the columnar organization of cortical circuits?

Radial glial cells

Why do we say that retinal ganglion cells are mainly responsive to differences in illumination that occur within their receptive fields?

Retinal ganglion cells respond best when a light or dark edge falls at the boundary between the center and surround regions of the receptive field.

At what neural site does habituation of a gill-withdrawn reflex occur in Aplysia?

Synapse between sensory and motor neuron

Which of the following substances will delay the axonal pruning of thalamocortical axons innervating visual cortex during development?

TTX

Sonic hedgehog (Shh) in the developing brain is derived from...

The notochord and floorplate

How is the hyperpolarization of a photoreceptor following exposure to a spot of light translated into depolarization of an ON-center retinal ganglion cell?

The reduced glutamate release by photoreceptors leads to enhanced firing of mGluR6 expressing bipolar cells

What is a receptive field?

The region of sensory space that stimulates changes in a single neuron's membrane potential

In the sensory homonculus below, why is the right hand so large relative to the left foot?

There is a decreased number of neurons in the right postcentral gyrus that respond to left foot stimulation than neurons in the left postcentral gyrus that respond to right foot stimulation.

Which statement best reflects the qualities of the retinotopic maps in the LGN and striate cortex?

They have more neurons devoted to central vision and fewer neurons devoted to peripheral vision.

What does it mean that V1 neurons have orientation selectivity?

They respond strongly to a particular orientation of a line, bar, or edge.

Recently, a competing lab has shown that Kctd13 is a key regulator of neural progenitor proliferation. Aberrant proliferation would be most likely to directly alter which of the following processes?

brain growth Possible answers: a. Axonal pathfinding b. neural tube closure c. brain growth d. hydrocephalus

Which neuroanatomical structure does not contain derivatives of the neural crest? Conversely, which do?

cerebral cortex Do: Peripheral nerve Dorsal root ganglion sympathetic ganglion

Which sensory receptor has one of the smallest receptive field areas and is crucial for sensing edges and points?

merkel cells

During development, DRG sensory neurons are derived from which of the following cell types.

neural crest

The transformation of embryonic ectoderm into the neural plate is known as

neurulation

Axonal growth cones are highly dynamic structures that extend wave like extensions known as [___x___] and finger like extensions known as [____y____].

x - lamellipodia y - filopodia