2022-02-01 09:23:03

Prelude (7:06)

Prelude (1:22)

Today’s topics

Warm-up

Neural structures that are “belly-ward” from the spinal cord are also called…

  • A. Dorsal
  • B. Ventral
  • C. Medial
  • D. Rostral

Neural structures that are “belly-ward” from the spinal cord are also called…

  • A. Dorsal
  • B. Ventral
  • C. Medial
  • D. Rostral

The blood/brain barrier is especially thin in which hindbrain area?

  • A. Pons
  • B. 4th ventricle
  • C. Cerebellum
  • D. Medulla oblongata (medulla)

The blood/brain barrier is especially thin in which hindbrain area?

  • A. Pons
  • B. 4th ventricle
  • C. Cerebellum
  • D. Medulla oblongata (medulla)

Which of the cerebral ventricles is most caudal (closest to the spinal cord)?

  • Cerebral aqueduct
  • Lateral ventricles
  • 3rd ventricle
  • 4th ventricle

Which of the cerebral ventricles is most caudal (closest to the spinal cord)?

  • Cerebral aqueduct
  • Lateral ventricles
  • 3rd ventricle
  • 4th ventricle

More neuroanatomy

Organization of the brain

Organization of the brain

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

Hindbrain

Structures adjacent to 4th ventricle

  • Medulla oblongata
  • Cerebellum
  • Pons

Hindbrain

Medulla oblongata

  • Fibers of passage (to/from spinal cord)
  • Cranial nerves VI-XII
  • Cardiovascular regulation
  • Muscle tone

Cerebellum

  • “Little brain”
  • Dorsal to pons
  • Movement coordination, classical conditioning (associative learning), + ???

Pons

  • Bulge on brain stem
  • Neuromodulatory nuclei
  • Relay to cerebellum
  • Cranial nerve V

Midbrain

Midbrain components

Tectum

Tegmentum

Midbrain

Tectum

  • Tectum -> “roof”
  • Superior colliculus (reflexive orienting of eyes, head, ears)
  • Inferior colliculus (sound/auditory processing)

Tegmentum

  • Tegmentum -> “floor”
  • Species-typical movement sequences (e.g., cat: hissing, pouncing)
  • Cranial nerves III, IV

Tegmentum

  • Nuclei that release modulatory neurotransmitters (“neuromodulators”)
    • Dopamine (DA)
    • Norepinephrine (NE)
    • Serotonin (5-HT)

Forebrain

Forebrain Components

Diencephalon (“between” brain)

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

Hypothalamus

  • Five Fs: fighting, fleeing/freezing, feeding, and reproduction
  • Controls Autonomic Nervous System (ANS)
    • Sympathetic branch
    • Parasympathetic branch

Hypothalamus

  • Controls endocrine system via pituitary gland (“master” gland)
    • Anterior pituitary (indirect release of hormones)
    • Posterior (direct release of hormones)
      • Oxytocin
      • Vasopressin

Hypothalamus

Telencephalon components

  • Basal (not basil) ganglia
  • Hippocampus
  • Amygdala
  • Cerebral cortex

Basal ganglia

  • Skill and habit learning
  • Sequencing of movement
  • Example: Parkinson’s Disease

Basal ganglia

Basal ganglia

Basal ganglia

Hippocampus

Hippocampus

  • From Greek for “sea horse”
  • Immediately lateral to (inferior) lateral ventricles
  • Memories of specific facts or events, spatial locations
  • Implicated in Alzheimer’s Disease
  • Fornix projects to hypothalamus
  • Mammillary bodies

Amygdala

Amygdala

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

Next time…

  • Neuroanatomy III (The cerebral cortex and beyond…)
  • Quiz 1

References

ctdalilah. (2006, October). Pinky and the brain-brainstem. Youtube. Retrieved from https://www.youtube.com/watch?v=snO68aJTOpM

LeDoux, J. (2015, August 10). The Amygdala Is NOT the Brain’s Fear Center. Psychology Today. Retrieved from https://www.psychologytoday.com/blog/i-got-mind-tell-you/201508/the-amygdala-is-not-the-brains-fear-center

Samanthi. (2019, May). Difference between forebrain midbrain and hindbrain. https://www.differencebetween.com/difference-between-forebrain-midbrain-and-hindbrain/; Differencebetween.com. Retrieved from https://www.differencebetween.com/difference-between-forebrain-midbrain-and-hindbrain/

Wellcome Collection. (2012, May). Dissecting brains. Youtube. Retrieved from https://www.youtube.com/watch?v=OMqWRlxo1oQ