Neurotransmitters (1)

Acetylcholine (neurotransmitter)

- Peripheral Nervous System - Cortical activation - Attention, learning and memory - 1st neurotransmitter lost in Alzheimer's Disease

Synaptic Cleft

- Presynaptic Cell (terminal; top): sending the info; the axon terminal - Synaptic cleft (middle): the space between the neurons - Postsynaptic cell (dendrite or dendritic spine; bottom): receiving the info: dendrite

Dopamine (neurotransmitter)

- Reward and reinforcement - Cognition - Movement (Basal Ganglia) - Dysregulated in schizophrenia

Serotonin (neurotransmitter)

- Sleep - Anxiety - Mood - Appetite

Norepinepherine (neurotransmitter)

- Sympathetic Nervous System - Alertness/vigilance - Mood - Appetite

Can a neuron respond to more than 1 neurotransmitter?

- They can respond to many types of neurotransmitters - Whatever they have receptors for - Usually glutamate and GABA - and others

Metabotropic Summary

- do not have channels - Neurotransmitter binds --> G-protein on intracellular side of receptors is activated --> activated 2nd messenger --> many effects - Opens channels indirectly - Uses chemicals called second messengers - Relatively slow acting - Relatively long-lasting effects - Effects are more widespread and varied

Ionotropic Summary

- have ligand-gated channels - Neurotransmitter (ligand) binds --> channel opens --> ions pass through --> EPSP or IPSP - opens channels directly - relatively fast - relatively short - effects are localized

Glutamate (neurotransmitter)

- main excitatory NT - memory formation, etc

GABA (neurotransmitter)

- main inhibitory NT - GABA-A receptor targeted in anxiety treatment

Catecholamines*

1.) Dopamine 2.) Norepinephrine 3.) Epinephrine

Monoamines

1.) Dopamine 2.) Norepinephrine 3.) Epinephrine 4.) Serotonin

What neurotransmitters go into the group "monoamines"?***

1.) Dopamine 2.) Norepinephrine 3.) Epinephrine 4.) Serotonin

Compare iotropic and metabotrophic receptors

1.) Ionotropic Receptors - have ligand-gated channels - Neurotransmitter (ligand) binds --> channel opens --> ions pass through --> EPSP or IPSP - Faster, more transient effects 2.) Metabotropic Receptors - do not have channels - Neurotransmitter binds --> G-protein on intracellular side of receptors is activated --> activated 2nd messenger --> many effects - Slower, longer, lasting effects

Most neurotransmitters have:

1.) Only ionotropic receptors 2.) Only metabotropic receptors 3.) 1 type of ionotropic receptor and 1 type of metabotropic receptor 4.) Many types of ionotropic receptors and many types of metabotropic receptors

Two things that could occur when the G-protein is activated:***

1.) activated 2nd messenger 2.) many effects* or 1.) The G protein causes the ion channel to open, and ion pass-through

What are the others involved in?***

Acetylcholine - PNS - Cortical activation - Attention, learning, and memory - 1st NT lost in Alzheimer's disease

What happens to neurotransmitters when they are released?** (pg.81)

Calcium releases neurotransmitters from the terminals and into the synaptic cleft. The released molecules diffuse across the cleft and attach to the receptors. They separate and may be taken back into the presynaptic neuron for recycling or may diffuse away - Neurotransmitters bind to receptor proteins in the postsynaptic cell

Where do the initial precursors (the first thing in the synthesis pathway) for dopamine, norepinepherine, epinepherine, serotonin and acetylcholine come from (very general answer to this)?

Diet

Movement (basal ganglia) and reward/reinforcement, and dysregulated in schizophrenia

Dopamine

What neurotransmitters share a pathway of synthesis? Collectively what are they called?*

Epinephrine, norepinephrine, and dopamine share a pathway of synthesis. Phenylalanine is the precursor for these three.

Main inhibitory neurotransmitter

GABA - Gaba-A receptor targeted in anxiety treatment (benzodiazepines)

What is the most common inhibitory neurotransmitter?

Gaba

Main excitatory neurotransmitter

Glutamate

What is the most common excitatory neurotransmitter?

Glutamate

Where are neurotransmitters made (very general answer to this)?

In the cell body of a neuron* - or in the neuron

Neurotransmitter receptors that have a channel which opens when the neurotransmitter binds:

Ionotropic

What is the difference between ionotropic and metabotropic receptors?

Ionotropic - have ligand-gated channels - Neurotransmitter (ligand) binds --> channel opens --> ions pass through --> EPSP or IPSP - opens channels directly - relatively fast - relatively short - effects are localized Metabotropic - do not have channels - Neurotransmitter binds --> G-protein on intracellular side of receptors is activated --> activated 2nd messenger --> many effects - Opens channels indirectly - Uses chemicals called second messengers - Relatively slow acting - Relatively long-lasting effects - Effects are more widespread and varied

Two classes of neurotransmitter recepters

Ionotropic and Metabotropic

Neurotransmitter receptors that don't have a channel, but have a G-protein attached to the intracellular side:

Metabotropic receptor

Vigilance and sympathetic nervous system

Norepinepherine

Mood, appetite, sleep

Serotonin