Univ. of Illinois, Urbana-Champaign
Bio/Neuro 303
Chapter 11 - Study Questions
*** LAST UPDATED 03 October 2002 ***
90. In the vertebrate retina, the outer segments of the receptor cells point
toward the
a. front of the eyeball, and are the first part of the retina reached by
light entering the eye.
b. front of the eyeball, and are the last part of the retina reached by
light entering the eye.
c. back of the eyeball, and are the first part of the retina reached by
light entering the eye.
*d. back of the eyeball, and are the last part of the retina reached by
light entering the eye.
91. The nuclear layers of the vertebrate retina contain mainly
*a. neuron somata.
b. photoreceptor cells.
c. neuron terminals and synapses.
d. synapses and somata.
93. The plexiform layers of the vertebrate retina contain mainly
a. neuron somata.
b. photoreceptor cells.
*c. neuron terminals and synapses.
d. synapses and somata.
96. With which of the following cell types in the retina do horizontal cells
NOT synapse?
*a. Amacrine cells.
b. Bipolar cells.
c. Cone cells.
d. Rod cells.
97. With which of the following cell types in the retina do horizontal cells
NOT synapse?
a. Bipolar cells.
b. Cone cells.
*c. Ganglion cells.
d. Rod cells.
98. Which retinal cell type spans the inner and outer plexiform layers?
a. Amacrine cells.
*b. Bipolar cells.
c. Cone cells.
d. Ganglion cells.
100. The optic nerve consists of the axons of
a. bipolar cells.
b. horizontal cells.
*c. ganglion cells.
d. amacrine cells.
102. Which of the statements below explains why rods are more sensitive to
light than are cones?
a. Cones point away from the source of the stimulus.
b. Rods are inhibited by horizontal cells.
c. Cones connect only to bipolar cells.
*d. None of the statements a, b, or c explain the differences in
sensitivity.
103. Transduction in rod cells of the vertebrate retina takes place in the
*a. outer segment
b. inner segment.
c. nucleus area.
d. synaptic area.
104. Transduction in rod cells in a vertebrate eye is carried out by the
following sequence of events:
*a. activation of rhodopsin by light-->activation of
transducin-->activation of PDE-->breakdown of cGMP-->closure of Na+
channel.
b. activation of transducin-->activation of rhodopsin by
light-->activation of PDE-->breakdown of cGMP-->closure of Na+ channel.
c. activation of rhodopsin by light-->activation of PDE-->activation of
transducin-->breakdown of cGMP-->closure of Na+ channel.
d. activation of transducin-->activation of rhodopsin by light-->breakdown
of cGMP-->activation of PDE-->closure of Na+ channel.
105. The effect of light on vertebrate rod cells is to
*a. reduce sodium conductance and thus hyperpolarize the cell.
b. increase sodium conductance and thus depolarize the cell.
c. reduce sodium conductance and thus depolarize the cell.
d. increase sodium conductance and thus hyperpolarize the cell.
106. If you could somehow selectively destroy all the horizontal cells in the
retina, what would the effect on the receptive field of a bipolar cell
probably be?
a. None.
b. The receptive field would get larger.
*c. The inhibitory surround region would be lost.
d. The inhibitory surround area would become excitatory.
107. The inhibitory surround in the receptive field of a bipolar cell of a
salamander is probably due to
a. parallel processing in the lateral geniculate nucleus.
*b. inhibitory action by horizontal cells.
c. inhibitory action by amacrine cells.
d. inhibition by the graded responses of ganglion cells.
108. The electrical response recorded in horizontal cells when the retina is
stimulated by light is a
a. post-synaptic potential with spikes.
*b. post-synaptic potential without any spikes.
c. generator potential, since spikes are produced.
d. receptor potential, since no spikes are produced.
109. The electrical response recorded in bipolar cells when the retina is
stimulated by light is a
a. post-synaptic potential with spikes.
*b. post-synaptic potential without any spikes.
c. generator potential, since spikes are produced.
d. receptor potential, since no spikes are produced.
111. Which of the following retinal cell types shows an inhibitory surround
effect in its receptive field?
a. Horizontal cells.
*b. Bipolar cells.
c. Rods.
d. Cones.
112. Bipolar cells differ from all other cell types in the retina in that they
a. do not generate spikes.
b. may hyperpolarize in response to light on their receptive fields.
*c. make synaptic contact with all other cell types in the retina.
d. show a center-surround receptive field.
118. Amacrine cells differ from horizontal cells in that amacrine cells
a. connect to bipolar cells.
*b. can generate spikes.
c. connect to cells of their own type.
d. respond to light striking their receptive fields.
119. Ganglion cells in the retina
a. show generator potentials when stimulated.
b. may be inhibited by amacrine cells.
*c. may show either center-on OR center-off responses.
d. hyperpolarize when stimulated.
120. The electrical response recorded in ganglion cells when the retina is
stimulated by light is a
*a. postsynaptic potential with spikes.
b. postsynaptic potential without any spikes.
c. generator potential, since spikes are produced.
d. receptor potential, since no spikes are produced.
121. "Off" center ganglion cells in a cat retina respond to a small spot of
light in the center of the receptive field by
a. increasing firing for the duration of the stimulus.
b. increasing firing only at the beginning of the stimulus.
c. giving no response (due to simultaneous inhibitory effects).
*d. ceasing background firing during the stimulus, and firing when the
stimulus is turned off.
122. Which of the following classes of retinal ganglion cells appear to be best
suited to help resolve detail in the fovea?
*a. X.
b. Y.
c. Z.
d. W.
123. Y-cells in the cat retina have
a. small receptive fields with sustained responses, and are concentrated
in the center of the retina.
*b. large receptive fields with transient responses, and are concentrated
outside the center of the retina.
c. large receptive fields with variable responses, and are concentrated in
the center of the retina.
d. small receptive fields with transient responses, and are scattered
throughout the retina.
124. X-cells in the cat retina have
*a. small receptive fields with sustained responses, and are concentrated
in the center of the retina.
b. large receptive fields with transient responses, and are concentrated
outside the center of the retina.
c. large receptive fields with variable responses, and are concentrated in
the center of the retina.
d. small receptive fields with transient responses, and are scattered
throughout the retina.
128. In the vertebrate visual system the distinctly different response proper-
ties of X, Y and W ganglion cells has been used as evidence for the idea of
*a. parallel processing.
b. serial processing.
c. trigger stimuli.
d. all of the above.
129. The discovery of X, Y and W ganglion cells in the retina of the cat
suggested that ______ is involved in visual processing.
a. inhibitory input from horizontal cells
b. multiple processing by bipolar and amacrine cells
c. serial processing
*d. parallel processing
132. In the human brain, the first relay station for visual signals is in the
*a. lateral geniculate nucleus.
b. medial geniculate nucleus.
c. primary visual cortex.
d. inferior colliculus.
133. The physiology of the cat visual cortex was investigated by
*a. Hubel and Wiesel.
b. Wald
c. Sperry.
d. Werblin and Dowling.
138. Visual cortex "simple" cells respond to
*a. bars of light with a particular orientation and position.
b. bars of light rotated at particular directions, but located anywhere in
their receptive fields.
c. edges oriented in particular directions, but located anywhere in their
receptive fields.
d. either a spot of light or an annulus (center-surround organization).
139. The most important feature(s) of a stimulus for the stimulation of a
simple cortical cell is(are)
a. its position but not its orientation.
b. its orientation but not its position.
*c. its position and orientation.
d. none of the above.
140. Some types of complex visual cortical cells respond strongly to
a. small spots.
b. uniform illumination.
*c. stimuli that have a corner.
d. closely spaced stationary straight lines.
141. A plausible explanation for the response properties of complex visual
cortical cells is that axons of
a. "W" cells project onto cells in the lateral geniculate nucleus.
b. complex cortical cells terminate on simple cortical cells.
c. simple cortical cells project onto complex cells in the lateral
geniculate nucleus.
*d. simple cortical cells terminate on complex cortical cells.
142. A complex cell responds mainly to
a. moving spots of dark against a luminous background.
*b. properly oriented edges.
c. corners moving in a definite direction.
d. complex features such as faces.
144. In the vertebrate visual system, the fact that there seems to be a
hierarchical organization in which more complex stimuli are required to
activate cells in higher levels of the hierarchy, has been used as evidence
for the idea of ______ in this visual system.
a. parallel processing.
*b. serial processing.
c. trigger stimuli.
d. all of the above.
145. Feature extraction along the visual pathway refers to the
a. increasing complexity of center-surround relationships.
b. appearance of effects due to lateral inhibition.
c. refinement (i.e., loss of variability) of stimuli that can excite
neurons along the pathway.
*d. increasing complexity of the stimulus features which maximally excite
neurons farther away from the rods and cones.
146. Light entering a mammalian eye and striking the retina first passes
through the
a. photoreceptive layer.
b. outer nuclear layer.
c. inner nuclear layer.
*d. ganglion cell layer
147. The response of a horizontal cell to stimulus of its receptive field is
a. depolarizing and spiking.
b. hyperpolarizing and spiking.
*c. hyperpolarizing and non-spiking.
d. depolarizing and non-spiking.
148. Vertebrate rods and cones respond to light by
a. closing ligand gated Na+ channels.
b. opening second-messenger gated K+ channels.
c. opening ligand gated K+ channels.
*d. closing second-messenger gated Na+ channels.
149. Adaptation in rods and cones is modulated by
a. kinase-mediated changes in the receptor molecule.
*b. the levels of free calcium in the outer segment.
c. cAMP-mediated changes in a potassium channel.
d. desensitization of the photosensitive rhodopsin molecule.
150. A primary difference between the responses of simple and complex cells in
the visual cortex is
a. simple cells are responsive primarily to stimuli such as spots, while
complex cells are responsive primarily to light/dark boundaries.
b. simple cells are sensitive to boundaries alone, while complex cells
often require a particular orientation and position of the boundary as
well.
*c. simple cells require boundaries of particular orientation and position,
while complex cells are often insensitive to boundary position.
d. complex cells will respond to movement of simple spots, whereas simple
cells will not.