Hippocrates - when and what was important
400 BC, understood that thought, aesthetic pleasure and emotion took place in brain and maeks us who we are
What were da Vinci's and Michelangelo's role in brain perspective?
da Vinci gets a more accurate anatomical view by dissecting corpses.
Michelangelo drew a picture of god that looks like the brain.
Descartes? What theory is he responsible for? Why pineal?
To understand animals, we must view them like machines.
He is responsible for dualism - humans = physical machine with nonphysical soul at particular location in the body aka pineal gland. Bc it's singular and located at base and cneter of brain.
Is dualism right? Where did phineas gage have damage?
No, everything is purely physical. Pineal gland is for melatonin. Prefrontal cortex (planning, inhibition)
What is phrenology? What are sensitive periods? What does proper development of NS require?
Brain is functionally organized but everything else is wrong.
Periods of life in which plasticity is greater than it is in others.
Interaction with environment, especially depending on visual experience.
What are important characteristics of neuroanatomy? (4) define each
- 1. Cytoarchitecture - organization of cells (tightly packed, big small, etc, layers clusters)
- 2. Hodology - study of interconnections of brain cells and regions.
- 3. Developmental origin - important factor in species comparison. how brain regions in diff animals relate to each other evolutionarily
- 4. Form of cells
What is neuron doctrine? Who made it up? Is it right?
Brain is made of separate cells that are independent & info is transmitted from one cell to another across gaps.
Golgi thought it was all one continuous system with no gaps.
Substantiated w/ staining procedures - Golgi stain
What are the functions of the glia?4 are they neurons?
- (1) Insulation of axons in vertebrates
- (2) Important in development, but play supportive role to neurons
- (3) Immune response in nervous system
- (4) Contribute to synaptic transmission
aka astrocytes, microglial, oligodendrites (glial cell that makes myelin in CNS) vs. Schwann cells (peripheral)
What is a reticular formation?
Region in brainstem that regulates incoming activity "inquisitive dendrites" pick up info and send out axons widely throughout NS to affect arousal and sleep/wake
What are the four structural divisions of the neuron for info processing?
- 1. Input zone - dendrites (receive info from neurons, branched
- 2. Integration zone - cell body (nucleus) inputs are combined and transformed
- 3. Conduction zone - axon leads away from cell body.
- 4. Output zone - axon terminals are a functional output zone and communicate to other cells at synapses.
Multipolar neuron? Bipolar? Unipolar?
- Multipolar - lots of dendrites and one axon.
- Bipolar: 1 and 1
- Unipolar: single branch that leaves cell body one end is receptive pole and other is output zone.
What are 3 components of peripheral nervous systeM?
- Cranial - connects directly to brain (brain stem)
- Spinal - connects to spinal cord.
Autonomic nervous system- supplies neural connections to glands and smooth muscles of organs.
Where do sensory neurons enter spinal cord? Motor neurons?
Sensory - dorsally, motor ventrally.
Where do f,m, and h brain come from? do all vertebrates have these? which animals have large cerebral hemispheres? difference between humans and rats?
neural tube, yes.
Mammals and birds
What is in the limbic systme?
- 1. Hippocampus
- 2. Amygdala
- 3. Septum
What cephalons are f,m,and h brains split into?
F: telencephalon (cortex, basal ganglia, limbic system) and diencephalon (thalamus, hypothalamus)
H: metencephalon (pons and cerebellum) and myelencephalon (medulla)
What is in telencephalon? called what in mammals? Which parts are part of limbic system?
- 1. Iso/neocortex (3) - high level sensory processing, where motor commands are first initiated, integration of emotion, motivation and cognition.
- 2. Hippocampus - learning (spatial) & memory specialized yet integrative
- 3. Amygdala - emotion (trust, fear) social cognition, motivational behavior
- 4. Septum - inputs into hippocampus important for learning. Interacts w/ amygdala to impact & regulate emotional responses.
- 5. Basal ganglia - get input from midbrain and project to cortex in a loop. Important for motor contorl, learning, modifying amplitude of motor output (important developmentally)
What happens with lesioned septum?
What's wrong in Parkinson's patients?
septal rage --> pathologically aggressive regardless of situation
Degenerative dopaminergic pathway to Ganglia
What's in diencephalon? (3)
Hypothalamus - thirst, hunger, hormones, sexual behavior, affects pituitary & gonadal activity
- Preoptic area
- Epithalamus - pineal gland
- Thalamus - gatekeeper between cortex and rest of brain and helps with focus and attention
What is midbrain also called? two parts? what is in each part?
1. Tectum - superior (visual) and inferior (auditory) colliculus. NOT reflex. contribute to sensory perception.
2. Tegmentum - sensory and motor neurons (i.e., cranial nerves) and reticular formation
What's in hindbrain? (3)
1. Cerebellum - layered, importnat for motor control (like BG). But BG is responsible for modifying amplitude and direction, while cerebellum is important for modifying plans of movement.
- 2. Pons - input for cerebellum
- 3. Medulla LIKE TEGMENTUM - cranial nerve nuclei for both motor and sensory, has important reticular formation. Main function - motor pattern generators for patterened life functions - breathing, heartbeat, etc.
Operational death is brainstem death (death of hindbrain and midbrain).
Even without motor output, people can respond to questions.
Why do we study non-human animals?
What are the methodological concerns? (4)
- 1. Ethics
- 2. Methodological concerns - possible approaches, convenience of housing, natural experiments (bats with inferior colliculus & giant squid axons), brain evolution.
1. Why do larger bodies need more brains? (4)
1. Same cognition and motor control as smaller animals (neuron:muscle fiber ratio) - so more neurons.
2. More innervation
3. More sensory information
4. Longer extremities = longer axons
What is allometric? What is deviation from the slope in brain weight vs. body weight? Can you use the same line across classes?
Brain size vs. body size - lower slope. Encephalization factor - different mass of brain than expected for body weight --> intelligence.
No. Must ensure level playing field.
Comparing brain size among species?
Role of selective pressures.
Must have experience AND genotype to accommodate experience
Birds that need to store food (higher i mountain) had larger hippocampuses for spatial memory as to where they stored their food. So, here we measured brain region size (hippocampus) vs. telencephalon
Bats have relatively large inferior colliculus size.
Define mosaic and concerted evolution and give examples of each
Mosaic - individual brain regions can evolve independently of rest of brain (inferior colliculus)
Concerted evolution - brain regions evolve together - coordinated changes.Developmental constraint Hippocampus can only get bigger if whole telencephalon gets bigger - basically if it gets to develop later (cells stop proliferating and start differentiating), it'll be disproportionately large. (cortex vs medulla)
What are consequences of large brains?