Invasive Physiological Research Methods

Invasive Physiological Research Methods

1. Stereotaxic Surgery

   • Use to position where to put an experimental device(s) within the brain
   • Stereotaxic Atlas
     • provides coordinates for locating structures within the brain
   • Bregma
     • A point on the top of the skull often used as a reference point
   • Sterotaxic Instrument
     • Used to hold head steady and guide the device to be inserted

2. Lesion Methods (Remove, damage, or destroy a part of the brain ---> part of brain = particular behaviour)

   • Aspiration lesions – suction cortical tissue
   • Knife cuts – may damage surrounding area
   • Radio-frequency lesions – heat destroys tissue
   • Cryogenic blockade – “reversible lesion”

3. Electrical Stimulation

   • Help activate a structure that has been removed from the brain (even a damaged brain)
   • Stimulation of a structure may have an effect opposite to that seen when the structure is lesioned

4. ·

   • Extracellular unit recording Firing of a neuron
   • Multiple-unit recording Firing of many neurons
   • Intracellular unit recording Membrane potential of a neuron
   • Invasive EEG recording

5. Invasive Electrophysiological Recording Methods

   • Intracellular unit recording (Membrane potential of a neuron )
     • Records membrane potential from one neuron as it fires
   • Extracellular unit recording (Firing of a neuron)
     • Records the electrical disturbance ---> each time an adjacent neurons fires
   • Multiple-unit recording (Firing of many neurons)
     • Small electrode records the action potentials of many nearby neurons
   • Invasive EEG recording
     • Picks up general changes in electrical activity

6. Drug Administration

   • Subcutaneously – SC – injected under the skin
   • Intragastrally (IG - into the stomach)
   • Intraperitoneally – IP – into the abdomen
   • Intramuscularly – IM – into the muscle
   • Intravenously – IV – into a vein
   • Oral
   • Intranasal
   • Cannula
   • Inhalation

7. Common Tests

   • Wechsler Adult Intelligence Scale
     • IQ Test (Often fails to detect memory deficits)
   • Token test
     • Can detect language-related deficits
   • Language lateralization
     • Used to identify language-dominant hemisphere
     • Dichotic listening – ear contralateral to dominant hemisphere shows superior hearing ability
     • Sodium amytal – anesthetize one hemisphere
   • Wisconsin Card Sorting Test
     • Test for frontal lobe damage

8. Behavioral Paradigms

   • Investigate a particular behaviour
   • Find common behaviors in species
     • Open-field test – general activity
     • Colony-intruder paradigm – aggression and defensive behavior
     • Elevated plus maze – anxiety
     • Tests of sexual behavior
   • Traditional conditioning paradigms
     • Operant conditioning
       • Reinforcement and punishment
     • Pavlovian conditioning
       • Pavlov's Dogs
       • Pairing an unconditioned stimulus with a conditioned stimulus
     • Self-stimulation
       • Animal works for electrical stimulation
   • Seminatural animal learning paradignms
     • Radial Arm Maze - tests spatial abilities
     • Morris water maze - tests spatial abilities
     • Conditioned Defensive Burying
       • Following a single aversive stimulus delivered from an object, rats will spray bedding at the object
       • Antianxiety drugs decrease the amount of burying behavior
     • Conditioned taste aversion
       • Mimic situations that an animal might encounter in its natural environment
         • Conditioned taste aversion occurs when a subject associates the taste of a certain food with symptoms caused by a toxic substance. The ability to develop a taste aversion is considered an adaptive trait or survival mechanism that trains the body to avoid poisonous substances before they can cause harm

9. Cognitive Neuroscience

   • Each complex cognitive process results from the combined activity of simple cognitive processes (constituent cognitive processes)
   • Each complex cognitive process is mediated by neural activity in a particular area of the brain
   • Goal is to identify the parts of the brain that mediate various constituent cognitive processes
   • Paired-image subtraction technique – compare PET or fMRI images during several different cognitive tasks
   • Rat Sexual Behavior
     • Receptive Female Lordosis
       • Lordosis quotient = lordosis/mounts
     • Male Sexual Behavior
       • 1. # mounts to intromission 2. # intromissions to ejaculation 3.Interval between ejaculation and next mount

10. Constituent Cognitive Processes

    • complex cognitive processes results from combined activity of these simple cognitive processes

11. Rat Sexual Behavior Measures

    • Receptive Female Lordosis
      • Lordosis quotient = lordosis/mounts
        • Lordosis behavior----> presenting a body posture adopted by some mammals usually associated with female receptivity to sexual intercourse.
    • Measure of male sexual behavior
      • # mounts to intromission
      • # intromissions to ejaculation
      • Intervals (ejaculation and next mount)

12. Cognitive Neuroscience

    • Identify parts of the brain ---> interferes certain cognitive processes

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