2017-08-30 14:25:57

Today's Topics

Gross neuroanatomy

Brain anatomy through dance

Finding our way around

Anterior/Posterior

Medial/Lateral

Superior/Inferior

Dorsal/Ventral

Rostral/Caudal

Directional image

Bipeds vs. quadripeds

No matter how you slice it

Horizontal/Axial

Coronal/Transverse/Frontal

Sagittal (from the side)

Slice diagram

Supporting structures

Meninges

Ventricular system

Blood supply

Meninges

Dura mater

Arachnoid membrane

Subarachnoid space

Pia mater

Meninges

Ventricular system

Ventricles

Lateral (1st & 2nd)

3rd

Cerebral aqueduct

4th

Cerebrospinal fluid (CSF)

  • Clears metabolites during sleep (Xie et al. 2013).

Blood Supply

Blood Supply

Arteries

  • Circle of Willis

Blood/brain barrier

  • Cells forming blood vessel walls tightly packed
  • Active transport of molecules typically required

Blood/brain barrier

Area Postrema

Organization of the Nervous System

Central Nervous System (CNS)

  • Brain
  • Spinal Cord
  • Everything encased in bone

Peripheral Nervous System (PNS)

Organization of the brain

Major division Ventricular Landmark Embryonic Division Structure
Forebrain Lateral Telencephalon Cerebral cortex
Basal ganglia
Hippocampus, amygdala
Third Diencephalon Thalamus
Hypothalamus
Midbrain Cerebral Aqueduct Mesencephalon Tectum, tegmentum

Organization of the brain

Major division Ventricular Landmark Embryonic Division Structure
Hindbrain 4th Metencephalon Cerebellum, pons
– Mylencephalon Medulla oblongata

Hindbrain

Hindbrain

  • Structures adjacent to 4th ventricle
    • Medulla oblongata
    • Cerebellum
    • Pons

Medulla oblongata

Medulla

  • Cardiovascular regulation
  • Muscle tone
  • Fibers of passage
    • Ascending fibers (from body), a.k.a. afferents
    • Descending fibers (exiting brain), a.k.a., efferents

Cerebellum

  • “Little brain”
  • Dorsal to pons
  • Movement coordination, simple learning

Pons

  • Bulge on brain stem
  • Neuromodulatory nuclei
  • Relay to cerebellum

Midbrain

Midbrain components

Tectum

Tegmentum

Tectum

Tectum

  • "Roof" of the midbrain
  • Superior and inferior colliculus
  • Reflexive orienting of eyes, head, ears

Tegmentum

  • "Floor" of the midbrain
  • Species-typical movement sequences
  • Neuromodulatory nuclei
    • Norepinephrine (NE)
    • Serotonin (5-HT)
    • Dopamine (DA) – from ventral tegmental area (VTA)

Forebrain

Forebrain Components

Diencephalon

Telencephalon

Diencephalon

Diencephalon Components

  • Thalamus
  • Hypothalamus

Thalamus

Thalamus functions

  • Input to cortex
  • Functionally distinct nuclei (collection of neurons)
    • Lateral geniculate nucleus (LGN), vision
    • Medial geniculate nucleus (MGN), audition
    • Pulvinar, attention?

Hypothalamus

  • Five Fs: fighting, fleeing/freezing, feeding, and reproduction
  • Controls pituitary gland (“master” gland)
    • Anterior pituitary (indirect release of hormones)
    • Posterior pituitary (direct release of hormones)
      • Oxytocin
      • Vasopressin

Hypothalamus

Telencephalon

  • Basal ganglia
  • Hippocampus, amygdala
  • Cerebral cortex

Basal Ganglia

  • Skill and habit learning
  • Linked to Tourette syndrome, obsessive-compulsive disorder (OCD), addiction, movement disorders
  • Example: Parkinson's Disease

Basal ganglia

Basal ganglia

  • Striatum
    • Caudate nucleus
    • Putamen
  • Globus pallidus
  • Subthalamic nucleus
  • Substantia nigra (tegmentum)

Hippocampus

  • Immediately lateral to lateral ventricles
  • Memories of specific facts or events
  • Fornix projects to hypothalamus
  • Mammillary bodies

Hippocampus

Amygdala (“almond”)

  • Physiological state, behavioral readiness, affect
  • NOT the fear center! (LeDoux 2015).

Amygdala

Next time

  • Gilmore's cautionary notes
  • The cerebral cortex
  • The peripheral nervous system

References

LeDoux, Joseph. 2015. “The Amygdala Is NOT the Brain’s Fear Center.” Psychology Today. https://www.psychologytoday.com/blog/i-got-mind-tell-you/201508/the-amygdala-is-not-the-brains-fear-center.

Xie, Lulu, Hongyi Kang, Qiwu Xu, Michael J Chen, Yonghong Liao, Meenakshisundaram Thiyagarajan, John O’Donnell, et al. 2013. “Sleep Drives Metabolite Clearance from the Adult Brain.” Science 342 (6156). American Association for the Advancement of Science: 373–77. doi:10.1126/science.1241224.