Biology

Brain Bee Study Guide: Chapter 9 Kinds of Research

Brain Bee Study Guide Notes: Chapter 9 Kinds of Research

Brain Bee Study Guide: Students can prepare for their local, regional, national, and international Brain Bee competitions by studying Brain Facts, a resource published by the Society for Neuroscience. In this study guide, we have compiled study resources/study guide notes for Brain Bee students: Chapter 9 Kinds of Research in Brain Bee

Overview

  • Three types of Research
    • Animal Research
    • Imaging Techniques
    • Genomic Investigations
  • The knowledge that has been gained

Animal Research

  • Use of animals
    • Rats + mice= role of neurotransmitters in cell communnication
    • Mammals(rabbits and cats)= studies of vision and other senses
    • Invertebrates
      • Fruit Fly’s brain -is less complex than vertebrates
        • BUT, many similarities (i.e. eye)
      • Zebrafish – fertilized transparent eggs -good models
      • Sea slugs-for learning and memory study

Chemical Connections in the Nervous System

  • What do brain disorder treatments target? (Parkinson’s disease and ADHD (attention deficit hyperactivity disorder)
    • Answer: Synapse
  • Made possible using Rats and Mice
  • New Staining techniques
    • Look at pathways
    • Connections between different areas of the brain
  • Death of Neurons with neurotransmitter Acetylcholine (Alzheimer’s disease)
  • Parkinson’s disease
    • Nobel Prize Arvid Carlsson
    • Neurotransmitter dopamine depleted
    • Used pigeons
      • Highly concentrated in basal ganglia
        • Motor Function Brain
  • Parkinson’s causes Basal Ganglia Cells to DIE
    • Limiting production of dopamine
    • DRUG: Levodopa-converted to dopamine
  • Drug Addiction
    • Used RATS
    • Brain affected by drugs= REWARD pathway
    • Affect Learning + Memory
      • Causes craving for that drug
  • Learning and Memory
    • Nobel Prize Eric Kandel
    • Use Mammals to conduct research on memory
      • Too complicated
  • Use Simple Organism-Sea Slug
    • Robust Protective reflex-learning for sea slug
      • Could remain for days/weeks as short-term
  • Long-term=activate genes
    • Lead to growth of new synapses

Understanding Critical Periods

  • Monkeys + Cats
    • Determine Treatement for amblyopia
      • Reduced vision of eye
    • visual experiences guide development of visual circuits
      • Nobel Prize David Hubel and Torsten Wiesel

Sample Research Methods

  • Microdialysis
    • Measure amount of particular brain chemical found in a specified area of the brain
    • Chemical + Other Molecules transported within neurons

Visualize brain activity + track nerve fiber connections

-Inject radioactive amino acid into brain cells

  • Enzyme Horseadish peroxidase
    • Taken up by nerve fibers-later identified under microscope
  • Electrophysiology=study of electrical properties of neurons
    • Study Brain + diagnose like hearing loss
    • Assessed in infants
      • Electrodes placed on specific parts of hear
      • Make analysis based on time lapse between stimulus and response

Imaging

  • Positron Emission Tomography (PET)
    • Measure blood flow or energy consumption in brain
    • Detection of radioactivity emitted when positrons (positively charged particles) undergo decay
    • Introduce radioisotope in blood
      • Carried to different brain areas
      • shows Up depending on how hard neurons working
  • Single Photon Emission Computed Tomography (SPECT)
    • Like PET
    • Pictures not as detailed
    • not expensive
  • Magnetic Resonance Imaging (MRI)
    • High-quality, 3-D image oforgans and structures
      • NO x-rays or radiation
    • Noninvasive
  • Magnetic Resonance Imaging (MRI)
    • Patient lies in Magnet hollow place
    • Different atoms in brains resonate to different frequencies of magnetic fields
      • Background magnetic field
      • Second magnetic field (rotate, turn on and off)
      • Swing back-create signal-converted to image
  • Magnetic Resonance Imaging (MRI)
    • Lot of water + fat= bright image
    • little or no water= black

Magnetic Resonance Imaging (MRI)

  • Different: Diffusion rates of water
  • Magnetic Resoance Spectroscopy (MRS)
    • Measures Concentration of specific chemicals
      • Neurotransmitters (NOT Blood flow)
      • See new info on brain development
  • Functional Magnetic Resonance Imaging (fMRI)
  • Functional Magnetic Resonance Imaging (fMRI)
    • Compare brain activity Active vs Resting
    • Detect increases in blood oxygen levels

-Magnetoencephalography (MEG)

  -Weak magnetic fields emitted by neurons

-Only know when certains areas become active

  • Optical Imaging and Other Techniques
    • Shining weak lasers through the skull to visualize brain activity
    • Inexpensive + relatively portable
    • Near Infrared spectroscopy (NIRS)
      • observing how much light is reflected back from brain at each freqency
        • track blood flow
  • Event-related optical signal
    • Records how light scatters in response to rapid cellular changes
  • Transcranial Magnetic Stimulation (TMS)
    • Inducing electrical impulses in brain
    • Altering Magnetic fields

Gene Diagnosis

  • 20,000-25,000 pairs of genes
  • More than 7,000 disorders affect brain
  • Mutations occur in DNA
  • Microarrays
    • Find Chromosomal location of many genes
    • understand chance of condition affecting other members of family
  • Tracking down Genes
    • HTT -gene altered in patients wi Huntington’s disease
    • RB1, inherited retinoblastoma-eye tumor
    • X-linked gene DMD -Duchenne muscular dystrophy
    • Walker-Warburg syndrom-severe problem with brain, eyes and muscles
      • Five genes so far

-FMR1 gene-people with fragile X syndrome

inherited intellectual disability in males

-LIS1 -tell brain how to grow

mutation people-have smoother brains

-thus more seizures

-TSC1 and TSC2-Rett Syndrome associated with MECP2 too

Deletion of Parts of Chromosome 16-lead to autism

-MLL2 gene -Kabuki syndrome

congenital intellectual disabilities +abnormal facial features

Brain Bee Study Guide: Chapter 9 Kinds of Research

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