1. Copyright © 2004 Allyn and Bacon 1 Chapter 5 Methods and Strategies of Research This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network; preparation of any derivative work, including the extraction, in whole or in part, of any images; any rental, lease, or lending of the program.

2. Copyright © 2004 Allyn and Bacon 2  Experimental Ablation  Evaluating the Behavioral Effects of Brain Damage:  Experimental ablation: The removal or destruction of a portion of the brain of a laboratory animal; presumably, the functions that can no longer be performed are the ones the region previously controlled.  Lesion study: A synonym for experimental ablation.

3. Copyright © 2004 Allyn and Bacon 3  Experimental Ablation  Producing Brain Lesions:  Excitotoxic lesion: A brain lesion produced by intracerebral injection of an excitatory amino acid, such as kainic acid.  6-hydroxydopamine (6-HD): A chemical that is selectively taken up by axons and terminal buttons of noradrenergic or dopaminergic neurons and acts as a poison, damaging or killing them.

4. Copyright © 2004 Allyn and Bacon 4  Experimental Ablation  Producing Brain Lesions:  Sham lesion: A “placebo” procedure that duplicates all of the steps of producing a brain lesion except for the one that actually causes the brain damage.

5. Copyright © 2004 Allyn and Bacon 5  Experimental Ablation  Stereotaxic Surgery  Stereotaxic Surgery: Brain surgery using a stereotaxic apparatus to position an electrode or cannula in a specified position of the brain.  Bregma: The junction of the sagittal and coronal sutures of the skull, often used as a reference point for stereotaxic brain surgery.

6. Copyright © 2004 Allyn and Bacon 6  Experimental Ablation  The Stereotaxic Atlas  Stereotaxic atlas: A collection of drawings of sections of the brain of a particular animal with measurements that provide coordinates for the stereotaxic surgery.  Stereotaxic apparatus: A device that permits a surgeon to position an electrode of cannula into a specific part of the brain.

7. Copyright © 2004 Allyn and Bacon 7  Histological Methods  Fixation and Sectioning  Fixative: A chemical such as formalin; used to prepare and preserve body tissue.  Formalin: The aqueous solution of formaldehyde gas; the most commonly used tissue fixative.

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13. 13  Histological Methods  Fixation and Sectioning  Perfusion: The process by which an animal’s blood is replaced by a fluid such as a saline solution or a fixative in preparing the brain for histological examination.  Microtome: An instrument that produces very thin slices of body tissue.

14. Copyright © 2004 Allyn and Bacon 14  Tracing Neural Connections  Tracing Efferent Axons  Anterograde labeling method: A histological method that labels the axons and terminal buttons of neurons whose cell bodies are located in a particular region.  PHLA-L: Phaseolus vulgaris leukoagglutinin; a protein derived from kidney beans and used as an anterograde tracer; taken up by dendrites and cell bodies and carried to the ends the axons.

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16. 16  Tracing Neural Connections  Tracing Efferent Axons  Immunocytochemical method: A histological method that uses radioactive antibodies or antibodies bound with a dye molecule to indicate the presence of particular proteins of peptides.

17. Copyright © 2004 Allyn and Bacon 17  Tracing Neural Connections  Tracing Afferent Axons  Retrograde labeling method: A histological method that labels cell bodies that give rise to the terminal buttons that form synapses with cells in a particular region.  Fluorogold: A dye that serves as a retrograde label; taken up by the terminal buttons and carried back to the cell bodies.

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19. 19  Study of the Living Human Brain  Computerized tomography (CT): The use of a device that employed a computer to analyze data obtained by a scanning beam of X- rays to produce a two dimensional picture of a slice through the body.  Magnetic resonance imaging (MRI): A technique whereby the interior of the body can be accurately imaged; involves the interaction between radio waves and a strong magnetic field.

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21. 21  Recording and Stimulating Neural Activity  Recording Neural Activity  Microelectrode: A very fine electrode, generally used to record activity of individual neurons.  Single unit recording: Recording of the electrical activity of a single neuron.

22. Copyright © 2004 Allyn and Bacon 22  Recording and Stimulating Neural Activity  Recording with Macroelectrodes  Macroelectrode: An electrode used to record the electrical activity of large numbers of neurons in a particular region of the brain; much larger than a microelectrode.  Electroencephalogram (EEG): An electrical brain potential recorded by placing electrodes on or in the scalp.

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25. 25  Recording the Brain’s Metabolic and Synaptic Activity  2-deoxytglucose (2-DG): A sugar that enters cells along with glucose but is not metabolized.  Autoradiography: A procedure that locates radioactive substances in a slice of tissue; the radiation exposes a photographic emulsion or a piece of film that covers the tissue.

26. Copyright © 2004 Allyn and Bacon 26  Recording the Brain’s Metabolic and Synaptic Activity  Fos: A protein produced in the nucleus of a neuron in response to synaptic stimulation.  Positron emission tomography (PET): A device that reveals the localization of a radioactive tracer in a living brain.  Functional MRI (fMRI): A modification of the MRI procedure that permits the measurement of regional metabolism in the brain.

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28. 28  Measuring the Brain’s Secretions  Measuring the Brain’s Secretions  Microdialysis: A procedure for analyzing chemicals present in the interstitial fluid through a small piece of tubing made of a semipermeable membrane that is implanted in the brain.

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30. 30  Stimulating Neural Activity  Multibarreled micropipette: A group of micropipettes attached together, used to infuse several different substance by means of iontophoresis while recording from a single neuron.  Microiontophroesis: A procedure that uses electricity to inject a chemical from a micropipette to determine the effects of the chemical on the electrical activity of a cell.

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33. 33  Neurochemical Methods  Finding Neurons that Produce Particular Neurochemicals  In situ hybridization: The production of DNA complementary to a particular messenger RNA to detect the presence of the RNA.

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