week 2

Question 1

neuralia

Answer 1

animals with specialized cells for sensing and communicating with other cells

Question 2

bilateria

Answer 2

animals displaying bilateral symmetry and with front and back ends

Question 3

gastroneuralia

Answer 3

main neural components develop on ventral side

Question 4

notoneuralia

Answer 4

main neural components develop on dorsal side

Question 5

precursors of brains ____________ appeared ________ animals had heads and tails

Answer 5

Head Ganglia
AFTER

Question 6

whats the problem thats making scientist question if nervous systems evolved twice and evidence

Answer 6

• recent phylogenomic evidence concludes that Proferia (sponges) evolved after C. tenophora (comb jelly fish)
• the sponge genome also has copies of genes for:
  1. voltage gated ion channels
  2. SNARE proteins (syntaxin, SNAP25, synaptobrevin)
  3. NT synthesis enzymes
  4. ionotropic glutamate receptors

Question 7

3 parts of anthropod brain:

Answer 7

1. Protocerebrum
   
   • optic lobes, mushroom bodies, central complex
2. Deutocerebrum
   
   • antennal lobes
3. Tritocerebrum
   
   • mouth, descending nerve cord

Question 8

Primary brain subdivisions

Answer 8

Question 9

how did the vertebrate telencephalon evolve differently in birds and mammals

Answer 9

Question 10

Laminar Architecture (layers):

Answer 10

• appear to represent a neural circuit design for efficiently integrating multimodal information
• birds and mammals converged upon a similar patters with some key differences

Question 11

cortical layers:

Answer 11

Paleocortex = 3 layers
- pyriform cortex
- olfactory and emotions
Archicortex = 3-4 layers
- hippocampus
- memory and spatial navigation
- considered evolutionary precursor to 6 layered neocortex in telencephalon
Neocortex (most of brain) = 6 layers

Question 12

neocortex is outer layer

Answer 12

stains darkly bc stain targets cell bodies

Question 13

3d reconstruction of 5 columns in rat vibrissal cortex

Answer 13

• layers represent different stages of neurocomputational processing
• columns represent different stimulus features, places, muscles, etc.

Question 14

structure of the human neocortex:

Answer 14

Question 15

general neocortical activity

Answer 15

Layer 1: connections between neighboring columns
Layer 2/3: connections between other cortical areas
Layer 4: inputs from thalamus
Layer 5: outputs to midbrain, brain stem, and spinal cord
Layer 6: outputs to thalamus

Question 16

many different types of cortical interneurons:

Answer 16

1. found in different layers
2. synaptically target different cell types in cortex
3. histochemically distinct(contain different proteins)

Question 17

Chandelier cells (ChCs or axo-axonic cells):

Answer 17

• specialized GABAergic interneurons subtype that selectively innervates pyramidal neurons at the axon initial segment (AIS)
  
  • AIS = site of AP generation
• found in greater numbers and more complex in humans
  
  • have larger axons and morphologically more elaborate synapses as compared to other mammals
• genetic association btw these and schizophrenia was uncovered when disruption of a candidate gene for schizophrenia decreased the number of chandelier cells