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Fundamentals of Neuroscience, Part 3: The Brain - Coggle Diagram

- - - - Process
        
        Interpret
    - - Retina
        
        Optic Nerve
        
        Thalamus
        
        Visual Cortex
        
        Information is distributed to be precessed in both in sequencial and parallel and then assembled back
  - - - Pupil
        
        Lens
        
        Retina
        
        Optic Nerve
        
        Record light thgough photoreceptors
        
        Divided into 3 most import stages
        
        Photorecept
        
        1 more item...
        
        Internal transmission
        
        2 more items...
        
        Output
        
        1 more item...
        
        Receptive fields
        
        Area of visual field that causes action potencials on retinal ganglion cells when illuminated
        
        Center-surround organization
        
        2 more items...
        
        Focus objetcs (flexible len)
        
        Control the amout of light
      - Focus light through de pupil (fixed len)
    - - Move eye around
      - Automatic move to estabilize image
  - - - Optic chiasma
        
        Optic tract
        
        Thalamus
        
        Optic radiation
        
        Visual Cortex
        
        Primary Visual Cortex (V1)
        
        4 more items...
        
        Visual Pathways
        
        4 more items...
        
        Lesions of the visual cortex
        
        2 more items...
        
        Lateral Geniculate Nucleus (LGN)
        
        3 types of layers
        
        (M) Magnocellular
        
        2 more items...
        
        (P) Parvocellular
        
        2 more items...
        
        (K) Koniocellular
        
        1 more item...
        
        80% of activitie is feedback from the visual cortex
        
        These feedback signals reverberate, permitting EEGs to work
        
        Neurons crosses
        
        Right side of visual field to the left hemisphere
        
        Left side of the visual field to the right hemisphere
        
        !!! THIS IS NOT RIGHT EYE TO LEFT SIDE AND VICE-VERSA !!!
- - - - Needs a medium to travel
      - Variation of pressure in the medium
      - Properties
        
        Frequencie / Pitch
        
        Amplitude / Volume
        
        Speed = 343 m/s (way slower than light)
  - - - Ear drum / Tympanic membrain
        
        Middle ear / Ossicles
        
        Oval window membraine
        
        Inner ear / Cochlea
        
        Detects fluid vibration and generates electrical signals
        
        Snail shell
        
        Divided in three layers
        
        External layers
        
        1 more item...
        
        Middle layer
        
        3 more items...
        
        Perylimph is disturbed
        
        Basilar membrane is pressured
        
        1 more item...
        
        Vibrates fluid inside the cochlea
        
        Vibrates with the ear drum, exiting the oval windows membraine
        
        Controls de pressure transmitted to the inner ear, to protect from noise iduced damage
        
        Vibrates with the sound, exctiting the ossicles
      - Directs sound through the ear
    - - Conductive deafness
        
        Loss of audition caused by damage in the midde ear
        
        Can be solved with hearing aid devices that amplifies the sound
        
        Mualfunction of the ossicles, for example
      - Sensorineural Hearing Loss (SNHL)
        
        Loss of audition caused by damage in the inner ear
        
        Malfunction of hair cells, for example
        
        Can be solved (partially) with a cochlear implant
  - - - Cochlear nucleus (CN)
        
        Keep the spacial organatization of the signal (tonotopy)
        
        Superior olive
        
        Inferior colliculus
        
        Thalamus
        
        Medial Geniculate Nucleus (MGN)
        
        Auditory cortex
        
        Primary auditory cortex (A1)
        
        2 more items...
        
        A2
        
        1 more item...
        
        Information is replicated in both hemispheres of the auditory cortex
        
        2 more items...
        
        Coordination responses to auditory stimuli
        
        Encode differencies in intensity and wheter is the right or the left ear
        
        Bypass
      - Signal is emitted
  - - - These neurons will generate acttion potencial only if both signals reach them at the same time, so the neuron activated represent the time delay between the signals
        
        Interaural Time Difference (ITD)
        
        Examples
        
        The neuron activated is closer to the right ear
        
        The left sinal had to travel a longer distance
        
        It was generated first
        
        The source of saound is closer to the left ear
        
        The neuron activated is at the middle
        
        Both signals traveled the same distance
        
        Both signal was generated at the same time
        
        Source of wound is the same distance from both ears
        
        Low frequency signals
    - - Interatural Level Difference (ILD)
      - High level signals are closer than low level signals
      - High frequency signals
    - - Pinna shape helps to overcome it
      - It's not known how the brain do this so perfectly yet
- - - - Sugar
      - T1R + T1R3 receptors
    - - Na and K
        
        Positive ion channels
    - - Bases and toxins
      - TR2 receptors
    - - Acids
      - Protons
    - - Glutamate and aminoacids
      - T1R1 + T1R3 receptors
  - - - Taste papilae
        
        Taste buds
        
        Taste receptors
        
        Gustatory nerves
        
        Distributed uniformly all over the tongue
  - - - Knockout mouse
        
        Knock out (destroy) a type of recepctor
      - Gene add
        
        Insert the gene of receptor on a cell that don't express that receptor
        
        Inserting a bitter recetor on a sweet cell of muse makes it to enjoy bitterness
  - - - Thalamus
        
        Anterior Insular Cortex
        
        Ventral Portermedial Nucleus (VPM)
        
        Brodman Area 3B
- - - - Dogs = 80%
      - Humans = 60 ~ 70%
    - - Amout
      - Timing
      - Order
      - Position
  - - - Olfactory cleft
        
        Cribiform plate
        
        Olfactory nerve
        
        Olfactory bulb
        
        Initial processing
        
        One for each hemisfere
        
        Mitral cells
        
        Glomeruli
        
        2 more items...
        
        Ofactory tract
        
        Limibic system
        
        5 more items...
        
        Primary olfactory cortex
        
        Regeneration
        
        First cranial nerve (CN1)
        
        Bone that separates the nose from the brain
        
        A lesion here can avoid information from passing to the ofactory bulb
        
        Total loss of sensing smell
        
        Anosmia
        
        Epithelium
        
        Detects odorants
        
        3 cm^2 reange
        
        3 cell types
        
        Support
        
        Basal
        
        Ofactory sensory neurons (OSN)
        
        At least 7 or 8 odorants to generate action potencial
        
        Slow responses (up to 2s)
      - Channel
      - Warm up
      - Filter
      - Humidify
      - Localization (two nostrils)
- - - - Cutaneous sensations
        
        Touch
        
        Mechanoreceptors
        
        4 types
        
        Pressure
        
        Hot
        
        Cold
        
        TRP channels
        
        Termoreceptos
        
        Also reacts to some chemicals like pepper or mint
        
        Pain
        
        Nociceptors
        
        Free nerve endings
        
        Tissue damage
        
        Intensity = firing frequency
  - - - Primary neuron
        
        Secondary neuron
        
        Thalamus
        
        Tertiary neuron
        
        Primary Somatossensory Cortex (S1)
        
        Somatotopic map
        
        Cerebellum
        
        Information crosses sides
        
        Dorsal root ganglion (DRG)
- - - - Walking
      - Standing
      - Speaking
      - Looking
      - Reflexes (non voluntary)
    - - Cardiac
        
        Heart
      - Smooth
        
        Internal organs
      - Skeletal
        
        Motor activity
        
        Structure
        
        Myocyte / myofiber
        
        Sarcomer
        
        Actin
        
        Myosin
        
        Facial muscles are controled directly by axons
        
        Precise movements (facial expressions)
  - - - Motor unit
    - - Radial map
      - Medial-lateral
      - Flexor-extensor
    - - Dorsal root ganglion cells
      - Upper motor neurons
      - Spinal interneurons
  - - - Involuntary
      - Fastest signals on the body
      - Short
      - Automatic
      - Myotatic Stretch Reflex
        
        Aumatically correts muscle contraction to avoid it from stretching
        
        E.g: Correcting posture
        
        Monosynaptic
        
        1ms
        
        Muscle
        
        Spindles (proprioceptors)
        
        Primary afferent neuron
        
        Motor Neuron
        
        Extrafusal muscle fibers
        
        1 more item...
        
        Dendrites
        
        Secondary afferent
        
        Gama motor neuron
        
        Intrafusal motor neurons
        
        1 more item...
    - - Recurrent circuits in loop
        
        A fires B that fires A that fires B...
      - Don't need sensory input
      - Locomotion
  - - - Dorsolateral pathway
        
        Distal muscles
        
        Foreamrs, legs, fingers, toes, etc....
      - Voluntary behavior
    - - Ventromedial pathway
        
        Proximal muscles
        
        Arms and thighs
        
        Midline muscles
        
        Trunk, abdomen, etc...
      - Autonomic functions
  - - - Complex movements
    - - Planning movements
    - - Somatotopic map
      - Upper motor neurson
        
        Direction
        
        Force
        
        Amplitude
        
        Sequence
      - Simple movements
- - - - Medulla
        
        Autononomical functions
        
        Breathing
        
        Swallowing
        
        Heart beat rate
        
        Blood pressure
        
        Breathing
      - Pons
        
        Nerve bridge from medulla to the midbrain
    - - Learning movement
      - Modulate motor activity
      - Main cells
        
        Parkinje cells
        
        Potencialize success signals
        
        Granule cells
        
        Inhibit fail signals
  - - - Superior coliculus
        
        Vision reflexes
      - Inferior coliculus
        
        Audition reflexes
    - - Dopamine
      - Subtantia nigra nigra
  - - - Information hub
      - Awareness
        
        Lesion/disturb can cause permanent coma or fatal familian insomnia
    - - Modulate motor signals
      - Learning movements
      - Pathways
        
        Direct
        
        Excitatory (increase activity)
        
        Thalamus
        
        Indirect
        
        Inhibtory (descrease activity)
        
        Both pathways work together
        
        Hypotesys: one pathway exictes a patter while the other inhibts the competitive patterns
        
        Parkinson's Desease: not enough dopamine to excite desired pattern and inhibit competitive patterns at the same time, causing trouble to control iniciante and control movement
        
        Huntington's Desease: damage on inhibtory pathway, causing involuntary movements that looks like voluntary movements