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					  Class is Cancelled!
  Tuesday, Oct 16th
Midterm #1 – Thursday, Oct. 4th
   Due Oct 25th
   Sign-up sheet for “lab component” located outside my
    office (Sn 1061)
   Sign-up for 1 hour slot – 4 people/time slot
       Monday, Oct 1st - Friday, Oct. 5th

   TA
       Catherine Lau
           Office hour: Wednesday, 1-2 (SN 3092E)
       Phillip MacCallum
           Office hour: Thursday, 2-3 (SN 1052)
Release of Neurotransmitters
 Figure 2.31

       3. Neurotransmitter is released into the
         synaptic cleft.
1) Ionotropic
 Receptor that
 contains a binding
 site for a
 neurotransmitter and
 an ion channel that
 opens when a           Figure 2.34
 molecule of the
 attaches to the
 binding site.
1) Short cut                       2) Second                         Figure 2.35

               2) Metabotropic Receptors
• Slower variety (short cut faster than second messenger system)
• Actions are reliant on activation of G-proteins located in the internal
         membrane of the postsynaptic cell
• 2 basic varieties: 1) short cut 2) second messenger
                                       Figure 2.36

Ionic Movement During Postsynaptic Potentials
Summary Slide
   Stop the signal
       Re-uptake
       Enzymatic Degradation
       Diffusion

   Autoreceptors

   Summation
       Temporal
       Spatial
CHAPTER 3   Structure of the Nervous System
Directions in the Nervous System

 Anterior/Rostral= Front
 Posterior/Caudal = Back
 Dorsal = Top
 Ventral = Bottom
 Lateral = Toward the side
 Medial = Toward the midline
 Ipsilateral= Same side
 Contralateral= Opposite side
                                 Fig. 3.1

             Fig. 3.2

      Brain Slices and Planes
Coronal *Cross Section or *Frontal Section
  Transverse section at right angles to the neuraxis.

                 Fig. 3.2

         Brain Slices and Planes
Sagittal Section
   •   Section parallel to neuraxis and perpendicular to the ground.
   •   Midsagittal Plane – special type of sagittal section through the
       corpus callosum separating the hemispheres.
            Fig. 3.2

     Brain Slices and Planes
Horizontal Section
  Section made through the brain parallel to the ground.

The MENINGES      Meninges
                      Dura Mater – tough, flexible
                       outermost layer.

                      Arachnoid Membrane – middle
                       layer of the meninges.
                          Subarachnoid Space – space
                           between arachnoid membrane and
                           pia mater filled with CSF.

                      Pia Mater – last layer of the
                       meninges, which adheres to the
                       surface of the brain.
                                                                Figure 3.6
                                                                  Obstructive
              Figure 3.4

              The Ventricular System
   CSF surround the brain (protection)
   Four ventricles (lateral-2, third and fourth connected by cerebral aqueduct)
   Choroid plexus- produces CSF (125 ml/day)
   Arachnoid granulations: absorb CSF
Development of the CNS

   Begins around 18th
    day after conception

   A patch of tissue
    on the dorsal
    surface of the
    embryo becomes
    the neural plate
Development of the CNS

Neural plate folds to form the neural

                                        Figure 3.7
Development of the CNS

   The neural groove then
    fuses to form the neural

   Walls of the neural tube
    become the CNS

   Neural crest becomes the
                               Figure 3.7
                                                  Figure 3.8

           Brain Development

   Early and later development of the human nervous system
Cellular Development

 Totipotent  – earliest cells have the ability to become
 any type of body cell
   Stem   cells

 Multipotent   – with development, neural plate cells
 are limited to becoming one of the range of mature
 nervous system cells
   Progenitor     cells
Migration of Neurons
   Once cells have been created through cell division in the
    ventricular zone of the neural tube, they migrate

   Migrating cells are immature, lacking axons and dendrites

   Inside-out migration

   Progenitor cells have limited capacity to replicate

   First Step: Symmetrical Division
       Progenitor -> progenitor
       Increases the size of the ventricular zone

                                                      Figure 3.10
      Second: Asymmetrical Division
•development where a progenitor cell
divides into one progenitor cell and one
brain cell

         Asymmetrical division (7 weeks after conception)
             First produces radial glia
             Cell bodies of RG in the VZ and processes extend to the pia
             Guide the migration of new neurons (neurogenesis)
             Ends after 3 months
Cellular Development and Migration

   Cajal-Retzius cells
     Develop   after radial
     Migrate to just inside
      the pia (Layer 1)
     Orderly migration:
       Build on each
        successive layer
       All end up below C-R
Anatomical Subdivisions
  Anatomy Basics
Major Division   Ventricle   Subdivision     Principle Structures
                                                   Cerebral cortex
                   Lateral   Telencephalon          Basal ganglia
   Forebrain                                       Limbic System
                   Third     Diencephalon
                 Cerebral                                Tectum
  Midbrain                   Mesencephalon
                 aqueduct                              Tegmentum

  Hindbrain        Fourth    Metencephalon
                             Myelencephalon       Medulla oblongata
The Forebrain
 Largest section of the
 brain, comprised of the:

   Telencephalon
        Cerebral hemispheres
           Cerebral Cortex
           Limbic System
           Basal Ganglia

   Diencephalon
        Thalamus
        Hypothalamus           Figure 3.8
The Forebrain

 Telencephalon  – contains
 most of the cerebrum.                Figure 3.8

 1.   Cerebral Cortex – thin,
      wrinkled layer of tissue
      covering the brain
      consisting of sulci (groove),
      fissures (big groove), and
      gyri (convolution).
         Frontal Lobe
         Parietal Lobe
         Temporal Lobe
         Occipital Lobe

                                                   Figure 3.16
The Forebrain
                                                   Figure 3.16
 Telencephalon
  Primary     cortices         Figure 3.15
       Visual cortex
       Auditory cortex
       Somatosensory cortex
       Motor cortex

  Association     cortices
       Associated with all primary

                                              Figure 3.16
 Limbic System

2.   Limbic System – set of
     structures involved in
     learning, memory, and
     emotion. Major structures
     of the limbic system
        Limbic Cortex (cingulate!)
        Hippocampus
        Amygdala
        Fornix
        Mammillary Bodies (part of   Figure 3.19
         the hypothalamus)
                                  Figure 3.20
     Basal Ganglia
3.   Basal Ganglia – set of
     structures involved in
     processing information for
     motor movement. Major
     structures of the basal
     ganglia motor system
        Caudate Nucleus
        Putamen
        Globus Pallidus
Forebrain: The Diencephalon
   Thalamus and

   Thalamus:
     Dorsal diencephalon
     Two lobes connected by
      the massa intermedia
     Many nuclei
         LGN
         MGN                       Figure 3.8
         Cerebellum->VLN-> motor
Forebrain: The Diencephalon

   Below thalamus
   Many nuclei
   Many diverse
   Endocrine- Pituitary

                             Figure 3.21

                           Hypothalamus regulates the autonomic nervous
                           system, controlling the pituitary gland, and
                           integrating species-typical behaviors.
Hypothalamic Portal System
   Endocrine system
       Hormones are secreted from the hypothalamus through the
        venous portal system to anterior pituitary

       These stimulate hormone release from AP
           Can control other glands or the hormones are the messengers
           AP- ‘master gland’
                Gonadotropin-releasing hormone causes the anterior pituitary gland
                 to secrete gonadotropic hormones, which play a role in reproductive
                 physiology and behavior

   Hypothalamus also releases hormones in the posterior
        oxytocin - stimulates milk ejection and uterine contractions during childbirth
        Vasopressin - regulates urine output by the kidneys
     The Midbrain
   Also known as the
    mesencephalon and is
    comprised of the tectum and

       Tectum (roof) – contains the
        superior (vision) and inferior
        (auditory) colliculi (singular is
        colliculus).                                      Figure 3.8

       Tegmentum (floor) – contains
        the periaqueductal gray matter,
        reticular formation, red nucleus,
        and substantia nigra all of
        which share a role in motor
                                            Figure 3.23c and d
The Hindbrain

   The Hindbrain

             both the
     Contains
     and the

                        Figure 3.8
  The Hindbrain

 Metencephalon   – a structure
 comprised of the cerebellum
 and the pons.

     Cerebellum – appears as a
      mini brain and is involved in
      motor coordination.

     Pons – contains part of the
      reticular formation and is
      involved in sleep and arousal.
                                       Figure 3.23
  The Hindbrain

 Myelencephalon     –
 contains the medulla
 oblongata containing
 portions of the reticular

   Is involved in basic life
    functions, such as
    respiration and regulation
    of the cardiovascular        Figure 3.23
     The Central Nervous System
   The Spinal Cord
     Function: distribute motor
      fibers to the effector organs
      of the body (glands and
      muscles) and to collect
      somatosensory information
      to be passed on to the brain
     Protected by the vertebral
       Composed    of 24 individual
Primary Components of the
Spinal Cord
  Spinal  Roots – a bundle of
   axons surrounded by
   connective tissue that occur in
   pairs, which fuse and form a
   spinal nerve
  Dorsal Roots – the spinal roots
   that contain incoming
   (afferent) sensory fibers
  Ventral Roots - the spinal
   roots that contain outgoing
   (efferent) motor fibers
The Peripheral Nervous System
   Somatic Nervous System
       Portion of the PNS comprised of the spinal nerves and
        cranial nerves involved in transmitting sensory information
        and controlling voluntary movement.
         Spinal Nerves
                Peripheral nerves attached to the spinal cord.
           Cranial Nerves
                Set of 12 motor and/or sensory nerves attached to the
                 ventral surface of the brain.

   The Autonomic Nervous System
      Portion of the PNS concerned with the regulation of smooth
       muscle, cardiac muscle, and glands
  The Autonomic
  Nervous System
 Sympathetic       Division of the
   Nervous system components
   involved in arousal and
   preparing the body for the
   expenditure of energy.
        ‘Fight or flight’
 Parasympathetic            Division of
 the ANS
   Nervous system components
   involved in relaxing the body,
   often competing with those of
   the sympathetic division.
        ‘rest and digest’

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