Neuropsychology
CH 5: Communication between neurons
Acetylcholine: chemical that communicates to inhibit or slow heart rate
Epinephrine: increases heartbeat (norepinephrine / noradrenline)
neurotransmitters carry messages + allow activity of a neuron
Ach neurons and NA neurons play complementary roles in controlling body
→ Acetylcholine (Ach) neurons parasympathethic nervous system “rest and digest”
→ Noradrenaline (NA) neurons sympathethic nervous system “fight or flight”
neurotransmitter can be inhibitory or excitatory; depending on the receptor
Synapse: information from neuron to neuron
- Action potential reaches axon terminal → depolarizes membrane
- (voltage-gated) Calcium channels open; influx of Ca+ into terminal
- Calcium influx triggers synaptic vesicles to release neurotransmitters : exocytosis
- Neurotransmitters bind to receptors on dendritic spine
! from presynaptic membrane to synaptic cleft to postsynaptic membrane
Source: https://www.sciencefacts.net/synapse.html
Receptors: receive transmitter substance
- depolarizes membrane : excitatory reaction
- hyperpolarizes membrane: inhibitory reaction
Autoreceptors: interact with self receptors on own presynaptic membrane
type I synapse: excitatory (located on shafts or spines of dendrites)
type II synapse: inhibitory (located on cell body)
Criteria for identifying a neurotransmitter:
1) must be synthesized in a neuron
2) neuron must be released when neuron is active + produce response
3) same receptor action when chemical is placed on target
4) must be mechanism of removal once work is done
, dendrodendritic synapse: dendrites message other dendrites
axodendritic synapse: axon terminal of neuron 1 synapses on dendritic spine of neuron 2
axoextracellular synapse: terminal with no specific target (ECF)
axosomatic synapse: axon terminal ends on cell body
axoaxonic synapse: axon terminal ends on other axon
axosecretory synapse: axon terminal ends on tiny blood vessel
axomuscular synapse: axon terminal via synaptic cleft to muscle
adrenaline: fight/flight
noradrenaline: concentration, emotion control → depression and mania
dopamine: pleasure, normal motor behaviour, pleasure → Parkinson’s, addiction
serotonin: mood → schizophrenia and OCD
GABA: calming
Acetylcholine: learning, maintain memory by neuron excitability → Alzheimer’s
glutamate: memory
endorphins: euphoria
neurons communicate by releasing chemicals at their terminal
“neurotransmitters released from the presynaptic membrane influence the activity of
postsynaptic neurons by binding to receptors on the receiving neuron and changing its
electrical activity: either exciting it to make action potential likely or inhibiting by making
action potential less likely”
neurotransmission (drugs can influence every step of the process)
● neurotransmitter synthesis and storage
● release from the axon terminal by exocytosis (due to increased Ca+ levels)
● action on postsynaptic receptors
● deactivation or re-uptake of neurotransmitter substances
ionotropic receptor: binding site for neurotransmitter + pore for ion flow mediates excitation
metabotropic receptor:uses second messenger mediates inhibition
CH 5: Communication between neurons
Acetylcholine: chemical that communicates to inhibit or slow heart rate
Epinephrine: increases heartbeat (norepinephrine / noradrenline)
neurotransmitters carry messages + allow activity of a neuron
Ach neurons and NA neurons play complementary roles in controlling body
→ Acetylcholine (Ach) neurons parasympathethic nervous system “rest and digest”
→ Noradrenaline (NA) neurons sympathethic nervous system “fight or flight”
neurotransmitter can be inhibitory or excitatory; depending on the receptor
Synapse: information from neuron to neuron
- Action potential reaches axon terminal → depolarizes membrane
- (voltage-gated) Calcium channels open; influx of Ca+ into terminal
- Calcium influx triggers synaptic vesicles to release neurotransmitters : exocytosis
- Neurotransmitters bind to receptors on dendritic spine
! from presynaptic membrane to synaptic cleft to postsynaptic membrane
Source: https://www.sciencefacts.net/synapse.html
Receptors: receive transmitter substance
- depolarizes membrane : excitatory reaction
- hyperpolarizes membrane: inhibitory reaction
Autoreceptors: interact with self receptors on own presynaptic membrane
type I synapse: excitatory (located on shafts or spines of dendrites)
type II synapse: inhibitory (located on cell body)
Criteria for identifying a neurotransmitter:
1) must be synthesized in a neuron
2) neuron must be released when neuron is active + produce response
3) same receptor action when chemical is placed on target
4) must be mechanism of removal once work is done
, dendrodendritic synapse: dendrites message other dendrites
axodendritic synapse: axon terminal of neuron 1 synapses on dendritic spine of neuron 2
axoextracellular synapse: terminal with no specific target (ECF)
axosomatic synapse: axon terminal ends on cell body
axoaxonic synapse: axon terminal ends on other axon
axosecretory synapse: axon terminal ends on tiny blood vessel
axomuscular synapse: axon terminal via synaptic cleft to muscle
adrenaline: fight/flight
noradrenaline: concentration, emotion control → depression and mania
dopamine: pleasure, normal motor behaviour, pleasure → Parkinson’s, addiction
serotonin: mood → schizophrenia and OCD
GABA: calming
Acetylcholine: learning, maintain memory by neuron excitability → Alzheimer’s
glutamate: memory
endorphins: euphoria
neurons communicate by releasing chemicals at their terminal
“neurotransmitters released from the presynaptic membrane influence the activity of
postsynaptic neurons by binding to receptors on the receiving neuron and changing its
electrical activity: either exciting it to make action potential likely or inhibiting by making
action potential less likely”
neurotransmission (drugs can influence every step of the process)
● neurotransmitter synthesis and storage
● release from the axon terminal by exocytosis (due to increased Ca+ levels)
● action on postsynaptic receptors
● deactivation or re-uptake of neurotransmitter substances
ionotropic receptor: binding site for neurotransmitter + pore for ion flow mediates excitation
metabotropic receptor:uses second messenger mediates inhibition
