Chapter 5
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The results of lesion studies are often difficult to interpret because
a particular neural circuit can perform only one behavior.
directly or indirectly, all regions of the brain are interconnected.
sometimes there is no clear difference between behavior and function.
the effects of surgical anesthesia cannot be determined.
Which of these methods produces the most selective brain lesions?
suction
microdialysis
excitatory amino acids
radio frequency current
To account for incidental brain damage when lesions are produced, researchers
increase the number of animals in the study.
use equal numbers of male and female animals.
produce sham lesions.
repeat the study.
A temporary or "reversible" brain lesion can be produced using
very low doses of an excitatory amino acid.
a local anesthetic.
electrical current on only one side of the brain.
a very brief interruption in the blood supply.
Using a stereotaxic apparatus, researchers can
assess loss of function resulting from brain lesions.
slice brains for histological examination.
make subcortical lesions in the brain.
confirm the location of brain lesions.
Using a stereotaxic atlas, researchers can
locate bregma.
determine the approximate location of structures deep within the brain.
calculate the correct amount of anesthesia required.
determine which method of making brain lesions to use.
A fixative performs all these functions except
attaching tissue to a microscope slide.
halting autolysis.
hardening tissue.
killing destructive microorganisms.
Using a microtome, researchers can
apply a mounting medium.
dry and heat tissue.
examine and photograph stained and mounted brain sections.
slice tissue into thin sections.
Scanning electron microscopes produce
moving images that can be preserved on video cassettes.
images cast on glass slides that can also be examined with a light microscope.
images of three dimensional structures.
images of tissue that cannot be exposed to light.
_____ labeling methods are used to trace _____ axons which carry information _____ a brain structure.
Retrograde; afferent; toward
Anterograde; afferent; away from
Retrograde; efferent; away from
Anterograde; afferent; toward
Immunocytochemical methods are used to
locate peptides and proteins.
provide a two-dimensional view of the human brain.
selectively destroy axons.
inhibit fast axoplasmic transport.
Researchers using CT or MRI
do not have to obtain permission from either the patient or the family.
can study the living brain without operating on the patient.
anesthetize the patient before beginning.
must first shave the patient's head.
Microelectrodes are used to record the electrical activity of
individual neurons in the brain.
entire regions deep within the brain.
the fluid that fills the ventricles.
the synaptic cleft.
2-deoxyglucose is
found in the membrane of cells.
a nuclear protein.
the preferred fuel of the brain.
not metabolized by cells.
An electroencephalogram is a
a microscope slide of radioactivity in the brain.
paper record of electrical activity in the brain.
x-ray record of normal or abnormal brain tissue.
treated photographic film showing receptor location.
The metabolic activity in the brain of a laboratory animal can be measured by giving an injection of _____ and analyzing the results using _____.
Fos; PET scanner
2-DG; autoradiography
fluorogold; high-performance liquid chromatography
saline; electroencephalography
Functional MRI (fMRI)
was the first imaging technique for studying the living brain.
images were never as detailed as those obtained using PET scanners.
permits the measuring of regional metabolism.
can be used to locate any radioactive substance.
Microdialysis is used to measure the
permeability of the cell membrane.
intracranial pressure.
secretions of the brain.
electrical activity of the brain.
An advantage of chemical stimulation over electrical stimulation of the brain is that
it requires less equipment.
stereotaxic surgery is not necessary.
the effects are more localized.
no tissue is destroyed.
To study the effect of chemicals on the activity of a single cell researchers use
microiontophoresis.
in situ hybridization.
single-unit recording.
autoradiography.
One of the difficulties in using electrical brain stimulation as a research tool is stimulation
sometimes triggers a seizure.
is difficult to localize.
must always be administered during open head procedures.
can never duplicate natural neural processes.
To identify neurons producing a particular peptide, researchers use _____ methods.
immunocytochemical
anterograde tracing
autoradiographic
retrograde tracing
To search for a particular messenger RNA, researchers use
the Fos protein.
autoradiography.
in situ hybridization.
2-DG.
Double labeling techniques permit researchers to determine what chemicals a neuron contains and
their connections with other neurons.
the enzymes that produce them.
the messenger RNA involved in their synthesis.
nearby agonists or antagonists.