Psych 2

• Neuropsychology


  Field focused on studying the relationship between brain functions and corresponding behaviour, especially in humans
• Neuropsychology


  • Rapid advancements in our understanding as increasingly complex technologies and methods develop
• Behavioral Neuroscience


  Field focused on studying the biological bases of behaviour
• Behavioral Neuroscience


  • Includes humans and non-human animals
  • Ethology: the study of non-human animal behaviour, especially in nature
• Studying Brain Structures (Neuroanatomy)

  1. Post-mortem investigations of brain tissue

  2. Visual inspection of larger sections, smaller samples

  3. Aided by microscopes of increasing complexity

  4. Stains developed to allow visualization of individual cells and structures

  
• Golgi stain


  Randomly stains about 5% of neurons in a slide
• Myelin stain


  Taken up by the fatty myelin surrounding axons
• Nissl stain


  Identifies cell bodies of neurons
• Optical (Light) Microscopes


  Bounce light off a sample and funnel through lenses that bend and magnify the image produced

  
• Scanning Electron Microscopes (SEM)

  Electrons bounce off sample and are collected to produce 3D images of the surface
• Transmission Electron Microscopes (TEM)


  Thin slices of sample to see inside the cell

  
• Autoradiography


  Stains and reveals which neurons are active

  
• Immunocytochemistry


  Uses antibodies attached to a dye to identify cell components
• Multi-photon Excitation Microscopy


  Fluorescence imaging technique that can image living tissue up to about 1mm thick

  
• In situ hybridization


  Construction of DNA strands which complement an mRNA strand
• Procedural Memory


  Behavioural tests
• Case Studies


  • Investigate behaviour of individuals with existing damage
  • Changes in behaviour since damage?
  • Differences in abilities versus control individuals?
• Ablation


  Surgical removal of brain tissue, often done by aspiration
• Lesioning


  Surgical damaging of neural tissue, precise and sometimes reversible
• Compensation


  Neuroplasticity; modification of behavior after damage to make up for lost functionality
• Temporary Lesion Techniques


  • Regional cooling
  • Local administration of a GABA
  • Transcranial Magnetic Stimulation (TMS)
• Stereotaxic instrument


  Device allowing precise positioning of a probe in the brain

  
• Direct electrical stimulation


  Activate an area, or interrupt existing activity
• Deep Brain Stimulation (DBS)


  Implant electrodes into targeted area and stimulate with low-voltage electrical current

  
• Chemical stimulation via cannulation


  Directly introduce drugs, neurotransmitters, etc.
• Microdialysis


  A more complex variation of cannulation
• Optogenetic techniques


  Light-sensitive protein channels can be inserted in specific types of neurons so that exposure to light selectively activates only that type of cell
• CRISPR-Cas9


  Can cut into and adjust the DNA of any cell, remove sections (silence a gene) or add sections (introduce new genes)
• Chemogenetics


  Insert synthetic sequences to give cells receptors sensitive to designer drugs
• Transcranial magnetic stimulation (TMS)


  Noninvasive technique using a magnet coil to induce a voltage, device held over scalp and pulsed at varying rates
• Transcranial direct current stimulation (tDCS)


  Noninvasive brain stimulation technique

  
• Single-cell recording


  Extracellular or intracellular recording via electrodes
• Electroencephalography (EEG)


  Electrodes measure summed graded potentials of all neurons in an area, high temporal resolution but low spatial resolution

  
• Event-related potentials (ERPs)


  Looking at patterns in the graded potentials on dendrites triggered by a sensory stimulus

  
• Magnetoencephalography (MEG)


  Magnetic potentials generated by neurons electrical field recorded by detectors on the skull, allows 3D visualization of active cell groups

  
• Computed tomography (CT)


  Produces flat static images that can be combined into 3D composites via computer, passes X-rays through the brain at different locations

  
• Magnetic resonance imaging (MRI)


  Produces static, 3D images, passes strong magnetic field through the brain followed by a radio wave

  
• Diffusion Tensor Imaging (DTI)


  Variant on MRI that detects directional movement of water molecules, shows pathways and potential blockages
• Magnetic Resonance Spectroscopy (MRS)

  Variant on MRI that detects the concentration of brain metabolites, useful in detecting persisting abnormalities in brain metabolism
• Functional magnetic resonance imaging (fMRI)

  Changes in the oxygen content of the blood alter the magnetic properties of the water in the blood, allows monitoring of changes to blood oxygenation as activity changes