ion channels to behaviour

Question 1

What are the degrees of reductionism?

Answer 1

• Macro anatomical
• Micro anatomical
• Macro molecule level

Question 2

What is macro anatomical?

Answer 2

• interaction of different brain areas

Question 3

What is micro anatomical?

Answer 3

• interaction of different brain cells

Question 4

What is macro molecule?

Answer 4

• interaction of individual protein molecules

Question 5

How do neurons connect?

Answer 5

• connect at the synapse, joining a terminal button of one neuron to the dendrite of another.

Question 6

Structure of a neuron.
what does the soma do?
What do the dendrites do?

Answer 6

• soma = integrates information
  dendrites = receives information from other neurons, through branches.

Question 7

What does the axon do in the structure of a neuron?

Answer 7

• gets information away from the cell body to another neuron.

Question 8

What is an action potential?

Answer 8

an all or nothing response, that occurs when there is a change in charge from the resting membrane in a positive direction.

Question 9

When is depolarisation triggered?

Answer 9

• at 50mv

Question 10

What is 50mv?

Answer 10

• the threshold of excitation, meaning an action potential is triggered.

Question 11

what is the resting membrane potential (RMP)?

Answer 11

• the difference in the + charge outside the cell and the - charge inside the cell. called 70mv

Question 12

Explain an ion transporter.

Answer 12

• it moves sodium ions outside of neurons and exchange for potassium ions inside cell, creating a shift, causing more moves of sodium ions than potassium.

Question 13

What is depolarisation?

Answer 13

• membrane becomes less negative

Question 13

what is the role of the post synaptic neuron?

Answer 13

• output, receives info at the synapse, then takes info out.

Question 13

what is polarisation?

Answer 13

• membrane becomes more negative?

Question 13

what does it mean to have something very localised?

Answer 13

• movement of ions is small - more significant near membrane.

Question 13

What two things change during action potentials?

Answer 13

• permeability of membrane (channels open or not)
• electrostatic pressure (membrane voltage changes)

Question 13

What is the role of the pre-synaptic neuron?

Answer 13

• the input, bring info into the synapse

Question 14

what causes depolarisation?

Answer 14

• info transfer between neurons, causes depolarisation.

Question 14

What is hyperpolarisation?

Answer 14

• chloride channels open - chloride ions go in and make membrane more negative, causing it to be inhibitory (less likely for APs to fire).

Question 15

What is hyporpolarization?

Answer 15

• Sodium channels opened, sodium flows in, causing it to be excitatory (more likely to cause AP) - the more action potentials the more likely to reach the threshold.

Question 16

What are ligands?

Answer 16

• a chemical that interacts with a receptor.

Question 17

Where does the ligand interact?

Answer 17

• at the binding site

Question 18

Explain selectivity of binding.

Answer 18

only specific ligands will fit into specific receptor types.

Question 19

What is Affinity?

Answer 19

• how well a ligand binds to a receptor.
  (therefor high affinity means that receptors are saturated).

Question 20

What are the two types of receptors?

Answer 20

• Ionotropic receptor
• Metabotropic receptor

Question 21

What is ionotropic receptor?

Answer 21

• receptor is “directly coupled” to an ion channel.
  (faster process than metabotropic).

Question 22

What is metabotropic receptors?

Answer 22

• it is where the ligand binds to the post synaptic neuron on the outside, changing it’s 3D shape of the receptor, activating G-protiens, that are connected to the receptor inside the neuron. Activating intracellular signalling cascade.

Question 23

what are some reasons for why receptors can also be found on the presynaptic neuron?

Answer 23

• due to retrograde signalling
  or
• negative feedback.

Question 24

what is retrograde signialling?

Answer 24

• where the signal travels backwards from post to pre.
• can cause an effect on synaptic plasticity.

Question 25

What are the two types of neurotransmitters?

Answer 25

• amino acids
• monanimies

Question 26

Describe Glutamate.

Answer 26

• the most abundant NT
• an excitatory NT
• binds to at least 8 different receptors both ion and metabo

Question 27

Describe GABA.

Answer 27

• most abundant inhibitory NT
• binds to both ion and metabo

Question 28

Describe Glyicine.

Answer 28

• most unusual
• an amionacid (simplest one chemically).
• binds to inhibitory receptors in the spinal cord.
  co-agonist with glutamate at NMDA receptors in the brain

Question 29

Who said “Neurons that wire together, fire together”?

Answer 29

• Donald Hebb

Question 30

what does Long-term potentiation do?

Answer 30

• strengthens synaptic connections
• helps encode memories

Question 31

What is adaptive behaviour?

Answer 31

• experiences can be learnt
• may allow a person to rely on other senses hearing or smell.
  (e.g., someone may rely on crossing the road by what they hear rather than actually looking left and right).
• more dangerous now that most cars are becoming electric, meaning they are silient.