lecture 1

Question 1

what are the two types of cells in nervous tissue?

Answer 1

1. non neural cells in brains: glia

2. neurons

Question 2

how many genes are expressed in the brain total?

Answer 2

around 14,000

Question 3

how many genes are expressed ONLY in the brain?

Answer 3

around 6000

Question 4

what makes a neutron different from a liver cell?

Answer 4

many different shapes
each cell is unique 
each pathway is unique 
complex structure
expresses different genes

Question 5

what are the 2 classes of cells in the nervous system

Answer 5

neurons (excitable)

glia (non-excitable)

Question 6

what are the patterns of gene expression for KCa channels

Answer 6

in the same tissue, may have high/low expression of different KCa
therefor different gating properties and different amounts of calcium required to open each channel in the same tissue

Question 7

what is genetic heterogeneity at the cellular level

Answer 7

different patterns of gene expression in adjacent cells

Question 8

glial cells electrical activity

Answer 8

glial cells don’t generate electrical activity directly but are essential elements for neural electrical functions

Question 9

glial cells general characteristics

Answer 9

• replaced precursors through adulthood (made all the time)
• modulate synaptic functions
• play a role in brain metabolism (supply energy)
• regulate blood flow through capillaries
• immune type function
• provide a scaffold for neuronal migration during development

Question 10

glial cells role with K

Answer 10

maintain chemical homeostasis for K

- keep at a low concentration outside cells and high inside to set membrane potential

Question 11

what are the 4 classes of non-neuronal cells

Answer 11

1. astrocytes
2. oligodendrocytes or Schwann cells
3. microglial cells
4. ependymal cells (include radial glia)

Question 12

what is the difference between invertebrates and vertebrate non-neuronal cells

Answer 12

invertebrates do have glial close but not many and not as specialized

Question 13

where do epedymal cells derive from?

Answer 13

radial cells

Question 14

ependymal cells general characteristics

Answer 14

• endothelial cells that line ventricles
• may produce cerebrospinal fluid
• may serve as stem cells to make more glia

Question 15

what is a tanycyte?

Answer 15

a subtype of ependymal cells that line the 3d ventricle and extend into the hypothalamus
involved in transferring signals from CSF to CNS

Question 16

what helps neutrons migrate along the surface of radial glial cells

Answer 16

cell surface proteins

Question 17

what are the two types of myelinating glial cells?

Answer 17

Schwann cells and oligodendrocytes

- both are layers of lipids that increase electrical resistance

Question 18

oligodendrytes

Answer 18

• central nervous system
• 1 oligodendrocyte wraps up multiple axons
  “sausage roll”

Question 19

Schwann cell

Answer 19

• peripheral nervous system

- myelinates 1 section of a motor neuron

Question 20

what are migroglia

Answer 20

phagocytotic cells

Question 21

microglia characteristics

Answer 21

main element of the intrinsic immune system
sense brain injury and clear cellular debris
derived from hemopoietic stem cells in bone marrow

Question 22

what are microglia implicated in

Answer 22

brain inflammatory responses, cognitive deficits, percussive brain injury, stroke damage

Question 23

are microglia static

Answer 23

no they are constantly retracting in and out to probe their environment

Question 24

what is synaptic pruning

Answer 24

microglia going in and tidying up weak synapses in order to carve away extra membrane

Question 25

what are 3 astrocyte functions

Answer 25

1. sequestration and or redistribution of K during neural activity 2. removal of glutamate and GABA at synapses 3. synthesis of precursor for glutamate and GABA production

Question 26

what glial cell is associated with cancer

Answer 26

astrocytes - proliferation of glia

Question 27

what glial cells are essential to the blood-brain-barrier

Answer 27

astrocytes | form tight junctions

Question 28

what kind of metabolism does the brain use

Answer 28

aerobic- requires breakdown of glucose | synaptic activity is coupled to glucose usage

Question 29

how do astrocytes regulate blood flow to brain regions

Answer 29

control arteriole diameter | changes in Ca

Question 30

why are capillaries so close to neutrons in the brain

Answer 30

to keep diffusion differences short and concentrations high

Question 31

what happens when there is a decrease in oxygen to the brain

Answer 31

body signals astrocytes to increase blood flow

Question 32

how can you use light absorbance to measure brain activity

Answer 32

shine light on surface of brain and look at amount of light reflected black oxygenated and deoxygenated hemaglobin have different properties shining green light shows change in volume not oxygen. shining red light - deoxygenated will absorb more

Question 33

functional magnetic resonance imaging (fMRI)

Answer 33

dynamic, based on paramagnetic properties of oxygen and deoxygenated hemaglobin active parts will use more oxygen

Question 34

magnetic resonance imaging (MRI)

Answer 34

static image, based on water distribution (density)

Question 35

CT scan

Answer 35

good for imaging structure, but not activity can tell you where something happens multiple pictures and reconstructed

Question 36

positron emission tomography (PET)

Answer 36

``` measures metabolic activity in biochemically specific neutrons ex. dopaminergic, seratonergic using short lived isotopes inject isotopes (precursors for neurotransmitters) taken up by neutrons that make NT ```