Lec 5 Chemistry of Behavior

Question 1

What are the different types of axon connections

give an example of their behavior

Answer 1

Axo-dendritic:
Majority of connections
mostly excitatory but can be inhibitory
Axo-somatic:
Mostly inhibitory
Axo-axonic:
Usually inhibitory, mediate/modulate things
Dendro-dendritic:
Perception based (smells, sight)

Question 2

Describe steps of Synaptic Transmission

Answer 2

1. action potential arrives at presynaptic terminal.
2. Voltage-gated calcium channels open calcium ions enter the axon terminal.
3. Synaptic vesicles filled with neurotransmitter to
   release neurotransmitter.
4. Some transmitter molecules bind to special
   receptors in the postsynaptic membrane,
5. Membrane depolarizes - more likely to
   fire action potential

Question 3

What are two types of post-synaptic receptors

Answer 3

Ionotropic:
(fast acting)
Neurotransmitter binds to receptor and lets ions through

Metabotropic:
(slow acting)
Neurotransmitter binds to receptor which activates intracellular processes being:
- change how long ionotropic receptors are open for
- change proteins and DNA in neuron in the long term

Question 4

What/Where are electrical synapses

Answer 4

-very fast
-inflexible when compared to chemical synapses

Question 5

Criteria to be called a neurotransmitter

Answer 5

1. Substance is synthesized in presynaptic neurons and stored
   in axon terminals
2. Is released when action potentials reach axon terminals
3. Is recognized by receptors on postsynaptic membrane
4. Causes changes in the postsynaptic cell
5. Blocking its release interferes with the effects on the
   postsynaptic cell

Question 6

How can signals be turned off?

Answer 6

Diffuse away
Reuptake
Enzymatic breakdown

Question 7

What are and what is the job of glutamate and GABA

Answer 7

Amino Acid Neurotransmitters
Glutamate:
excitatory neurotransmitter that is very abundant

GABA:
inhibitory and prevents overexcitation (i.e. seizures)

Question 8

Acetocholine what it do

Answer 8

Muscle function, brain function

Question 9

dopamine neuronal function

Answer 9

control of voluntary function

Question 10

Roles of serotonin

Answer 10

anti depressant

Question 11

Norepinephrine role

Answer 11

mood and wellbeing