chapter 1 neuroscience

1. Draw a simple diagram of a neuron and label its components. In what ways are neurons specialized for communication? How do these specialized features distinguish neurons from other types of cells?

Answer: Neurons have axons and dendrites, structures for maintaining and transmitting electrical potential, and synapses, all of which allow neurons to establish connections and share information

12. An action potential is a(n) _______ change in the electrical potential across the nerve cell membrane. a. single b. all-or-nothing c. permanent d. random e. unidirectional Answer: b

b, all or nothing

1. Which part of DNA is transcribed into messenger RNA?

exon

. A mouse model is created through Cre/lox technology in which a gene is knocked out of the central nervous system only. Which region would continue to express the gene? a. Diencephalon b. Cerebellum c. Cerebral hemispheres d. Spinal nerves e. Brainstem Answer: d

spinal nerves

5. Which technique(s) would one use to: (a) find the boundaries between layers of the cortex; (b) determine where the axons from nucleus X project; (c) visualize neurons that make protein Y; and (d) examine the dendrites of neurons in region Z?

(a) Nissl stain (b) Administration of radioactive or fluorescent tracers (c) Immunohistochemistry; in situ hybridization (d) Immunohistochemistry using antibodies against dendrite proteins

16. Which feature distinguishes the four model organisms (mouse, zebrafish, fruit fly, and nematode) from other animals that have been intensively studied by neuroscientists? a. Ease of genetic analysis and manipulation b. Nervous system of substantial complexity c. Extensive and interesting behavioral repertoire d. Specific neural structures or behaviors of interest e. Expression of behaviors is reflex-only (i.e., no complex behaviors) Answer: a

. Ease of genetic analysis and manipulation

3. Which statement accurately describes neural and glial cells? a. In both types, mitochondria are concentrated in the cell body. b. The endoplasmic reticulum is concentrated in axons. c. Exocytosis and endocytosis are important for synaptic communication. d. Glial cells and neurons rapidly transmit long-range electrical signals. e. Neither cell type relies on cytoskeletal filaments. Answer: c

. Exocytosis and endocytosis are important for synaptic communication.

. Which structures are included in the central nervous system (CNS) and which are part of the peripheral nervous system (PNS)?

. Which structures are included in the central nervous system (CNS) and which are part of the peripheral nervous system (PNS)?

. The technique that first revealed the tremendous diversity of neuronal cell types, by revealing different cell bodies along with their processes, is a. the Nissl stain. b. the Golgi technique (stain). c. cresyl violet staining. d. fluorescence staining. e. electron microscopy. Answer: b

. the Golgi technique (stain).

What are the main types of glial cells, and what is the main function of each?

: (a) Astrocytes maintain an optimal environment for neural signaling; (b) microglia respond to injury within the nervous system; (c) oligodendrocytes and (d) Schwann cell produce myelin in the CNS and the PNS, respectively.

What characteristics of magnetic resonance imaging make it such an attractive research tool?

: MRI is a safe, noninvasive procedure that provides useful images of structure and brain function. It is also cost-effective.

Compare spatial and temporal resolution of functional magnetic resonance imaging (fMRI) to those of magnetoencephalography (MEG).

: Temporal resolution of MEG is superior to that of fMRI, but the fMRI is superior to MEG for spatial resolution.

2. Which technique first produced unequivocal support for the neuron doctrine of the nervous system (as opposed to the reticular theory)?

Electron microscopy of nervous tissue

The brain imaging technique that makes use of a narrow X-ray beam is called a. MRI. b. fMRI. c. PET. d. SPECT. e. CT. Answer: e

CT

. Which of Camillo Golgi's contributions enabled Santiago Ramón y Cajal to make observations that suggested that nerve cells are discrete entities?

Development of a staining method based on impregnation with silver salts

. What was the substance of the disagreement between Golgi and Cajal that, nevertheless, earned them both the 1906 Nobel Prize in Medicine or Physiology?

Golgi was a proponent of the "reticular theory," which stated that all nerve cells are connected, whereas Cajal argued that nerve cells are discrete entities, which is now known as the neuron doctrine.

hich statement best describes the function of a neuron with multiple, highly branched dendrites and one axon?

It integrates information from many neurons.

The structural brain imaging technique that relies on atoms behaving like small magnets is called a. MRI. b. EEG. c. PET. d. SPECT. e. CT. Answer: a

MRI

2. Glia are at least as numerous as neurons in the brain, yet neurons are the predominant focus of neuroscience textbooks. Why?

Neurons generate and conduct electrical and chemical signals, while glia primarily play a supporting role.

. Which function is a characteristic primarily of neurons only, and not glia?

Transmits action potentials

compared with projection neurons, axons from local circuit neurons (interneurons)

are shorter

27. Which brain research method is associated with the greatest safety concerns? a. Computerized tomography b. Magnetic resonance imaging c. Event related potential analysis d. Electroencephalography e. Transcranial magnetic stimulation Answer: a

a, computer tomography

23. From which part of the nervous system do cells that innervate neuromuscular junctions originate? a. Central nervous system (CNS) b. Peripheral nervous system (PNS) c. Somatic motor division of PNS d. Visceral motor division of PNS e. Autonomic nervous system Answer: a

a. Central nervous system (CNS)

6. Which of the following is not an established role for glial cells? a. Integrating information to assist neural computation b. Maintaining the ionic milieu surrounding nerve cells c. Hastening the propagation of neural impulses d. Assisting synaptic transmission via neurotransmitter uptake e. Providing scaffolds that assist neural development Answer: a

a. Integrating information to assist neural computation

. A transgenic mouse animal model is created that expresses both the Cre recombinase gene, under control of a promoter for a gene expressed only in muscle fibers, and an androgen receptor with loxP sites around exon 2. How will expression of the androgen receptor protein be altered in the transgenic mouse? a. The mouse will not express androgen receptor in muscle fibers. b. The mouse will not express androgen receptor anywhere in the body. c. The mouse will express increased levels of androgen receptor in muscle fibers. d. The mouse will express increased levels of androgen receptor everywhere in the body. e. The mouse will not express androgen receptor in the nervous system. Answer: a

a. The mouse will not express androgen receptor in muscle fibers.

8. Which statement about astrocytes is true? a. They play a role in the formation of the blood-brain barrier. b. They form myelin in the peripheral nervous system. c. They produce collagen in the central nervous system. d. They produce antibodies. e. They regulate the chemical environment of the peripheral nervous system. Answer: a

a. They play a role in the formation of the blood-brain barrier.

During the knee jerk reflex, the role of the spinal interneuron is to _______ the _______ muscle, allowing the leg to _______. a. inhibit; flexor; extend b. inhibit; extensor; extend c. activate; flexor; extend d. inhibit; flexor; flex e. inhibit; extensor; flex Answer: a

a. inhibit; flexor; extend

18. Cognitive neuroscience is concerned with a. perception. b. emotions. c. language. d. memory. e. All of the above Answer: e

all of the above

26. Neuroethology is the field devoted to studying complex behavior a. through specifically designed behavioral tasks. b. in the native environment. c. in a laboratory. d. during a limited number of trials. e. using invasive methods. Answer: b

b, in the native enviroment

22. Which component represents the peripheral nervous system? a. Nucleus (i.e., group of neurons) b. Spinal nerve c. Tract d. Column e. Commissure Answer: b

b, spinal nerve

5. A neuron that innervates (i.e., makes synaptic contact with) a large number of other neurons a. represents convergent neural signaling. b. represents divergent neural signaling. c. represents massive neural integration. d. must fire at very high frequencies to be useful. e. can fire only at very low frequencies. Answer: b

b. represents divergent neural signaling.

18. The in situ hybridization method is based on

b. using nucleic acid probes to detect mRNAs that encode specific genes.

13. The set of neurons and small ganglia associated with the digestive tract is called the _______ nervous system. a. peripheral b. autonomic c. enteric d. sympathetic e. parasympathetic Answer: c

c, enteric

15. Which glial cell type serves as a resident immune cell in the central nervous system? a. Glial stem cell b. Astrocyte c. Microglia d. Oligodendrocyte e. Schwann cell Answer: c

c, microglia

14. Which cell produces myelin in the nerves of the peripheral nervous system? a. Astrocyte b. Neuron c. Schwann cell d. Microglia e. Neural progenitor cell Answer: c

c, schwan cells

1. Which statement accurately describes the expression of genes in the nervous system? a. Every gene in the human genome is expressed in the CNS. b. Splice variants add diversity to brain function via beneficial mutations. c. Most of the genes in the human genome are expressed in the CNS. d. The genes that are expressed in the CNS are expressed equally in all neurons. e. A small subset of the total human genome is expressed in the CNS. Answer: c

c. Most of the genes in the human genome are expressed in the CNS.

10. An advantage that intracellular recordings have over extracellular recordings is that they a. are easier to obtain. b. can be obtained in many more parts of the nervous system. c. can record synaptic and receptor potentials. d. can record from many neurons at once. e. can alter the threshold potential. Answer: c

c. can record synaptic and receptor potentials.

. In which part of a neuron would most of the endoplasmic reticulum be concentrated?

cell body

7. Which intracellular component facilitates the processes of endocytosis and exocytosis underlying synaptic communication?

cytoskeleton

19. In the knee-jerk reflex, the afferent neurons a. innervate leg flexor muscles. b. innervate leg flexor and extensor muscles. c. innervate leg extensor muscles. d. are sensory neurons. e. are cranial nerves. Answer: d

d, are sensory neurons

The figure shows patterns of action potentials (vertical lines) in neurons that form the neural circuits for the knee-jerk reflex. Which pattern represents the activity of a flexor motor neuron? a. Top b. Second from the top c. Third from the top d. Bottom e. None of the above Answer: d

d, bottom

20. What is the role of interneurons in the knee-jerk reflex? a. Inhibition of motor neurons to all leg muscles b. Amplification of the response c. Dampen the pain of the hammer tap d. Relaxation of flexor muscles e. Transfer of signal from efferent to afferent neurons Answer: d

d, relaxiation of flexor muscles

4. The major proponent(s) of the neuron doctrine was(were)

d. Santiago Ramón y Cajal and Charles Sherrington.

13. The part of a synapse to which the contents of synaptic vesicles bind is called the a. presynaptic terminal. b. synaptic ending. c. axon terminal. d. terminal bouton. e. receptor. Answer: e

e, receptor

17. Which statement about a center-surround receptive field is false? a. It can be mapped by electrophysiological recording techniques. b. It is characterized by a circular center and a doughnut-shaped surround. c. It can involve an excitatory response (e.g., to touch). d. It can involve an inhibitory response (e.g., to touch). e. It is found only in primary sensory cortex. Answer: e

e. It is found only in primary sensory cortex.

A doctor taps the right knee in an individual who was in a car accident and has sustained damage to the right dorsal root of the lower spinal cord. Which motor response would you expect? a. Right leg extends b. Left leg extends c. Right leg flexes d. Left leg flexes e. Right leg remains motionless Answer: e

e. Right leg remains motionless

24. Why is the white matter lighter than the gray matter? a. These are just historic terms not representative of real colors. b. White matter is less dense than gray matter. c. White matter is more translucent than gray matter. d. White matter contains more Schwann cells, which are light in appearance. e. White matter is richer in myelin, which reflects more light than gray matter. Answer: e

e. White matter is richer in myelin, which reflects more light than gray matter.

16. In the mature central nervous system, glial stem cells with the properties of astrocytes can give rise to a. astrocytes. b. neurons. c. oligodendrocytes. d. astrocytes and oligodendrocytes. e. astrocytes, oligodendrocytes, and neurons. Answer: e

e. astrocytes, oligodendrocytes, and neurons.

2. Genomics is the analysis of

e. coding and regulatory DNA of an individual organism or a species.

25. The neurons whose synaptic connections with glandular cells trigger stomach secretions are located in a. the spinal cord. b. the brain stem. c. the ganglia located along the vertebral column. d. front of the vertebral column. e. the ganglia embedded in the wall of the stomach. Answer: e

e. the ganglia embedded in the wall of the stomach.

most neurons have

one axon hillock (initial segment)

Which statement best describes most neurons?

they are polaized