METHODS OF STUDYING THE NERVOUS SYSTEM Outline 1. Methods of Visualizing the Living Human Brain
a. Contrast X-rays b. Computerized Axial Tomography c. Magnetic Resonance Imaging d. Positron Emission Tomography e. Functional MRI
2. Scalp Electroencephalography 3. Invasive Physiological and Pharmacological Methods
a. Stereotaxic Surgery b. Lesion Methods c. Electrical Stimulation d. Pharmacological Methods
CT scan of a man struck by lightning – basal ganglia damage
PET Scan of Normal (left) and Alzheimer's Disease (right) Brains
Intracellular unit recording
Extracellular Unit recording
Routes of administration Intragastric (IG) Intraperitoneal (IP) Intravenous (IV) Subcutaneous (SC) Intramuscular (IM)
Many drugs cannot pass the blood-brain barrier Microinjection 6-hydroxydopamine (6-OHDA)
Measuring the Chemical Activity of the Brain: 2-deoxyglucose autoradiography
radioactive 2-DG is injected animal performs the behavior of interest animal is immediately killed its brain is removed and sliced the slices are coated with a photographic
emulsion After a few days in the dark
areas of the brain that were particularly active show up as dark spots of radioactivity
in vivo cerebral microdialysis
measurement of specific
neurotransmitters in living/behaving animals
Immunocytochemistry Finds Neurotransmitters and Receptors
Takes advantage of the immune reaction. Antibodies attempt to destroy foreign substances
(antigens) Often by attaching themselves to the antigen.
Antibodies for peptide neurotransmitters and receptors have been created by cell biologists.
The antibodies are labeled with a dye or radioactive element and then used to identify specific neuroproteins in slices of brain tissue
Crayfish brain stained with anti-serotonin antibody
Localization of postsynaptic proteins in a cultured neuron by immunocytochemistry.
Antibodies to the NMDA receptor are labeled Yellow.
Glutamate acts at NMDA receptors
The NMDA receptors are concentrated in the yellow patches along the dendrites.
In situ hybridization locates peptides and proteins in the
brain All peptides and proteins (including
enzymes) are synthesized according to information contained on the chromosomes.
mRNA carries the code for a protein of peptide from the DNA in the nucleus to the ribosomes.
In situ hybridization labeled hybrid RNA strands with a base
sequence complementary (opposite) to the mRNA for synthesizing the target neuroprotein are created The labeled RNA will attract its
complementary mRNA The hybrid RNA binds to the complementary
mRNA in the target cells This tells us where the protein or peptide
that we are interested in is being produced.
Labeled neurons in the hypothalamus – The tissue was exposed to labeled RNA that binds with mRNA for the synthesis of vasopressin (a peptide).
BEHAVIORAL RESEARCH METHODS OF BIOPSYCHOLOGY
Outline 1. Neuropsychological Testing
a. General Tests: The WAIS b. lateralization of Language c. Specific Tests of Memory d. Specific Tests of Frontal Lobe Function
2. Paradigms of Animal Behavior a. Analysis of Species-Common Behaviors b. Traditional Conditioning Paradigms c. Seminatural Animal Learning Paradigms
3. Conclusion: Converging Operations
WAIS Most neuropsychological assessments begin
with the Wechsler Adult Intelligence Scale (WAIS)
It has 11 subtests 6 comprise the verbal scale (e.g., digit span,
information, similarities) 5 comprise the performance scale (e.g., block
design, object assembly) The information subtest and the digit span
test are memory tests that comprise part of the WAIS
however, these are notoriously bad measures of memory.