lecture 3 *biology and cognition *

contact between neurons

1. directly on cell body
2. on the recieving antenas

recieve and send signals

synapse

1. axodentric
2. axoaxonix
3. axosomatic

terminal button on dendrite

terminal buttons on soma

terminal button on axon

the transport of neurotransmitters form the presynaptic to postynaptic

axon → microtubuli → terminal button → presynaptic membrane → postynaptic cleft

microtubule in the axon

in the terminal button

flow to the presynaptic membrane

in the postynaptic cleft

more dense

calcium

exocitosis

open voltage dependent calium channels → calcium inflow → realease of neurotransmitter

the protection connection → vesicels become one with the persynaptic membrane → split in cleft

1. kiss and run
2. merge and recicle
3. bulk endocytosis

synaptic vesicles travel to presynaptic membrane and release their neurotransmitter and immediately return

synaptic vesicles travel to presynaptic membrane and release their neurotransmitter and become part of the presynaptic membrane and later return

number of vesicles become part of the presynaptic membrane (becomes larger and larger ) until some part will pinch off and multiple vesicles will be made

the postsynaptic membrane has transmitter dependent ion channels

binding site of receptor

molecule of neurotransmitter attached to the biding site opens the ion channel

can lead to excitation of post synaptic or inhibitory

electric charge in the postsynaptic membrane, which makes the postsynaptic membrane to generate an action potential

when Na+ channel opens and Na+ enters a depolarisation of the postsynaptic neuron will occur

if the inside of the cell becomes less negative it is more likely to fire

an electric charge on the postsynaptic membrane, which is caused by the binding of inhibitory neurotransmitters and makes the postsynaptic membrane less likely to generate an action potential

when neurotransmitter opens Cl

inside the cell becomes more negative it is less likely to fire

reuptake

G protein that causes cell activity

1. binding neurotransmitter
2. activation of G protein
3. enzyme
4. second messenget
5. open ion channels
6. EPSP or IPSP
7. possynaptic cell

1. influx of Na+
2. efflux of K+
3. influx of Cl_
4. influx of Ca2+

depolarisation ( more positivive inside)

hyperopolarisatin ( less positive inside ) : make up for the influx of Na+

hyperpolarisation ( more negative inside )

activate enzyme

1. diffusion
2. reuptake
3. degradation
4. enzyme degradation

reuptake

ake up neurotransmitter from cleft back in the presynaptic terminal button (GABA)

enzymatic degenration

receptor in the presynaptic membrane

regulate the production and release of neurotransmitter by the neuron

metabotropic

1. reuptake NT ( G protein activates reuptake )
2. reduction NT relese (G protein closes Ca2+ channels )

neagtive : inhibitory

knee jerk reflex, also called patellar reflex, **sudden kicking movement of the lower leg in response to a sharp tap on the patellar tendon**

1. Acetyl Choline
2. Monoamines

1. catecholamines
2. indolamines

dopamine

norepinephrine

epinephrine

reinforcement and motor

alertness, fight / flight, sympathetic system

1. serotonine
2. glutamate
3. glycine
4. GABA

mood

excitatory, motor, learning

inhibition (spine), motor

inhibitory, motor

wander through the brain and sensitize/desensitize complete neutral networks (trough subthreshold depolarization or hyperpolarization )

1. peptides
2. nucleosides

amino acids coupled by peptide bond

vasopressin

oxytocin

part of DNA base pair bound to sugar

denosine accumulates during fay (makes you sleep)

*caffeine blocks adenosine receptors

1. competitive binding
2. non competitve binding

the drug binds where the neurotransmitter binds usually

influences ion channel to open

can have more receptors therefore is not competitive

it can help neurotransmitter to open or close the site

blocks or inhibits

helps or exibits

1. precursor
2. stimulates release of neurotransmitter
3. stimulates postsynaptic respirators
4. Drugs that block autoreceptors , increase synthesis / reseo of NT
5. Drug inactivates acetylcholinesterase

1. inactivate enzyme
2. prevent storage in vesicles
3. inhibits release of neurotransmitter
4. block postysnaptic receptors
5. drug stimulate autorcepetops, inhibits synthesiselease of NT
6. Drug block the reuptake

substance from which neurotransmitter is made

DOPA is one example precursor of dopamine