1 Neurons and Potentials

Question 1

What is a Golgi stain, and who developed it?

Answer 1

developed by Italian Golgi, improved by Ramon y Cajal ; silver staining technique visually revealing the neurites and cell body structures of neurons

Question 2

The Neuron Doctrine

Answer 2

The neuron is the structural and functional unit of brain activity (Ramon y Cajal)

Question 3

The law of dynamic polarization

Answer 3

The flow of information in a neuron (generally speaking) is one directional, starting at the aggregation of information based on information inputs (at dendrites) decides whether to fire an action potential (at axon hillock), which subsequently travels down an axon(s) into a synapse with the release of neurotransmitter(s)

Question 4

What is the relationship between STRUCTURE and FUNCTION in the brain? (examples)

Answer 4

Structure constrains / determines the possible electrical dynamics of the brain Function in turn can influence the emerging structures of the brain, as seen in neuromodulatory systems which can determine whether a synapse response to a particular neurotransmitter

Question 5

What are nuclei? (example)

Answer 5

Nuclei are collections of neurons with specificconnectivity for functionality

Question 6

I what does EEG measure?

Answer 6

measure collective activity of nuclei with local field potentials/ EEG

Question 7

What are the two primary functions of the hippocampus?

Answer 7

(CA1, CA3) determinism where you are memory

Question 8

What are the different levels of analysis in neuroscience, and the mechanisms for measuring each?

Answer 8

synapse : the electrical potential of a single synapse - single cell recording neuron : electrical potential of a single neuron - single cell recording nuclei : temporal resolution of a population of synapses - EEG/field potentials regions : temporal resolution of oxygenated blood flow in brain regions - fMRI

Question 9

Label the parts of the neuron

Answer 9

Question 10

Syanptic potentials are ________ while action potentials are __________

Answer 10

snaptic : continuous

action: all or nothing

Question 11

What part of the brain? What is its primary function

Answer 11

hippocampus: orientation & memory

Question 12

What kind of neuron? Where are these founds?

Answer 12

Pyramidal cells are found in the cerebral cortex, amydgala and hippocampus

Question 13

What kind of neuron?

Answer 13

Stellate neuron; found many places in the body; can be spinous or aspinous

Question 14

What are some of the parameters on which you can classify neurons?

Answer 14

1) Shape/Number of axons; 2) Location; 3) Spinous or Aspinous dendrites; 4) Which neurotransmitters they handle

Question 15

Equilibrium potential

Answer 15

The membrane potential at which the net change of ions across the membrane is zero, given the overall concentration of ions on either side of the membrane

Question 16

What are the different types of electrical potentials in the brain?

Answer 16

membrane potential

equilibrium potential

synaptic potential

action potential

Question 17

membrane potential

Answer 17

the voltage difference between the intracelluar and extracellular spaces [includes resting, synaptic and action potential]

Question 18

snaptic potential

Answer 18

a change in the membrane potential to a positive or negative value (excitatory and inhibitory) brought about by the influx of ions through the ion channels of the synapse

excitatory and inhibitory inputs from one neuron (at axon terminal button) onto another neuron (at dendrite or soma)

Question 19

ions move from areas of ______ concentration to ______ concentration

Answer 19

high to low

Question 20

typical ion charges … Na / K / Cl … and where they are typically found

Answer 20

Na + //extracellular

K + //intracellular

Cl- //intracellular

Question 21

What are the properties of Ion Channels?

Answer 21

ion selectivity: (e.g. Na+, Ca++, K+, Cl-)

gating: (e.g. by voltage, ligand)

kinetics (e.g. amount of time the channels remain open)

state (e.g. activated, inactive, deinactivated, persistent)

distribution (e.g. location on the neuron)

Question 22

What does a neurotransmitter do?

Answer 22

A neurotransmitter mediates information exchange between neurons, through the generation of synaptic potentials

Question 23

What are the three types of neurotransmitters?

Answer 23

Excitatory

Inhibitory

Neuromodulatory

Question 24

excitatory neurotransmitters

Answer 24

increase likelihood a neuron will fire an action potential by influencing the ion flow through the cell membrane; usually located on the dendrites

glutamate, ACh

Question 25

Inhibitory neurotransmitters

Answer 25

decrease the likelihood the neuron will reach threshold for action potential, by influencing the ion flow through cell membrane; usually found on the cell body

GABA, glycine

Question 26

Neuromodulatory neurotransmitters

Answer 26

NE, 5-HT, DA, HA, Ach

Question 27

What factors influence the speed of conduction of an action potential?

Answer 27

the axon length and myelination

Question 28

action potentials

Answer 28

all or non electrical events in a neuron, reflecting the spatial/temporal integration of synaptic potentials of the neuron, and the intrinsic excitability of the neuron. The neuron fires an action potential when the integration reaches its threshold

Question 29

What is the average resting potential for a neuron?

Answer 29

ranges from -40 to -90 milivolts; with the intracellular space being more negatively charged than the extracellular space

Question 30

What ions are generally found inside/outside the cell, at resting potential?

Answer 30

inside: K+ and negatively charged proteins;
outside: Na+ Cl-

Question 31

In an unstimuluated neuron, _____ ions pass from ______ to ______ the cell, through _____

Answer 31

K+ pass from inside to outside through potassium channels

Question 32

As more K+ ions leave the cell, the inside becomes more - charged, which then causes some K+ to be pulled back in; which then balances to a resting potential

Answer 32

TRUE