NEUR200-Unit2 UMD

Where are neurotransmitters released

into the synapse

What areas are affected by released neurotransmitters

neurons that have synapses within the releasing cell

Duration of effect of neurotransmitters

short term because of rapid uptake and breakdown

where are hormones released

into blood stream

what is affected by hormones

lots of cells

how long do hormone effects last

long term

4 types of transmitters

amino acid, peptide, steroids, gases

amino acid transmitters

glutamate, GABA, glycine, serotonin, melatonin, dopamine, norepinephrine, epinephrine, acetylcholine

peptides

endogenous opiates, oxytocin, vasopressin, endocannabinoids

steroids

estradiol, progesterone, corticosterone, testosterone

gasses

nitrous oxide

Dale's principle

a neuron will consistently release one type of transmitter

is Dale's principle true or false

false

What can you tell from neuron names

function

2 broad types of receptors

ionotropic, metabotropic

what do ionotropic receptors affcet

auditory and sensory systems

What happens when neurotransmitters bind to ionotropic receptors

ion channels open

how fast are the effects of ionotropic receptors

very fast, < 1 ms

what do ionotropic receptors provide the mechanism for

excitation/inhibition

what do metabotropic receptors affect

emotion/state regulation, sleep/wake cycle

what happens when neurotransmitters bind to metabotropic receptors

metabolic reaction

how fast are the effects of metabotropic receptors

slower than ionotropic receptors, >30 ms

2 types of ionotropic receptors

AMPA receptor, NMDA receptor

How are AMPA receptors gated

ligand-gated

What neurotransmitter binds to AMPA receptors

glutamate

what happens when neurotransmitters bind to AMPA receptors

the shape changes

what do AMPA receptors cause

EPSPs

How are NMDA receptors gated

ligand and voltage gated

what neurotransmitter binds to NMDA receptors

glutamate

What ions do NMDA receptors allow to flow through

Ca

What are the two requirements to allow Ca to flow through

glutamate must bind to it, cell must be depolarized

What are NMDA receptors important for

learning and memory

what do metabotropic receptors trigger

alters activity of cellular proteins, increases/decreases gene transcription

What receptors does GABA bind to

GABA-A ionotropic and GABA-B metabotropic receptors

What are metabotropic receptors coupled with

G-proteins

how do metabotropic receptor changes affect the cell

changes are slow so it affects cell activity and responsiveness

What is the net effect of metabotropic receptor activation

increased/decreased excitability of the cell by ionotropic receptor activation

5 stages of chemical transmission

synthesis, storage, release, receptor binding, inactivation

what do SNARE proteins do

causes synaptic vesicles to bind to membrane

what does ionic flux change

membrane potential

what are the steps of inhibiting glutamatergic neurons

glutamate will excite GABA, GABA inhibits neurons

4 main neurotransmitters

dopamine, acetylcholine, serotonin, norepinephrine

Dopamine major source

midbrain, SNc, VTA

Dopamine major receptors

D1-D5 metabotropic receptors

what does dopamine control

motivation, appetite, cognitive control, learning

if dopamine levels change, what does it cause

psychosis

what are some dopaminergic drugs

antipsychotics, stimulants, recreational drugs

how do dopamine drugs affect dopamine

prevents reuptake of dopamine

acetylcholine major source

basal forebrain

acetylcholine receptors

nicotinic (ionotropic) and muscarinic receptors (metabotropic)

what does acetylcholine control

memory and attention

if acetylcholine levels change, what does it cause

alzheimers

what system is acetylcholine usually found in

autonomic nervous system

what are some cholinergic drugs

acetylcholinesterase inhibitors, nicotine, scopolamine

serotonin major source

raphe nuclei

what are the major serotonin receptors

metabotropic 5HT1-5HT7 receptors

what does serotonin control

mood, sleep, wakefulness

when is serotonin the highest

when animals are awake

what are some serotonin drugs

SSRIs

norepinephrine major source

CNS: locus coerulus PNS: adrenal cortex

norepinephrine major receptors

metabotropic alpha and beta receptors

what does norepinephrine control

energy, arousal, attention, mood

what are some norepinephrine drugs

ADHD meds, BP meds

where are most neurotransmitters located

midbrain and brain stem

cells that make NDS, norepinephrine, dopamine, serotonin are located where

brainstem

what does NDS, norepinephrine, dopamine, and serotonin primarily act on

metabotropic receptors

pathways are important for

initiation, maintenance of behaviors, goal-oriented behaviors

reward pathway

VTA, nucleus accumbens

Nigrostraital Pathway

dopamine, SNC

what is the nigrostraital pathway historically referred to as

movement pathway

mesolimbic pathway

dopamine, VTA

what does mesolimbic pathway deal with

motivation

what does dopamine do

increases cell responsiveness to glutamate

5 classifications of exogenous ligands

agonists, antagonists, inverse agonists, allosteric modulators, uptake inhibitors

agonists

mimics endogenous ligands

antagonists

binds and prevents endogenous binding

inverse agonists

induces opposite effect of endogenous ligands

allosteric modulators

alcohol, xanax

agonist examples

nicotine, cannabis

uptake inhibitors

transport blockers

uptake inhibitor examples

cocaine, prozac

neurons in which region have a lot of nicotinic receptors

neurons in VTA

what type of channel are nicotinic receptors in

cation channel

what happens when nicotine binds to the receptors

depolarizes neurons

what do first gen antipsychotics block

d2 dopamine receptors

what are first gen antipsychotics used to treat

schizophrenia and positive symptoms

what do second gen antipsychotics block

d2 and serotonin receptors

where does alcohol bind

GABA-A receptors at binding site

what does cocaine block

dopamine uptake

where does the neural system develop from

ectodermal layer

what is found in neural tube

neural stem cells

5 steps of maturation

proliferation, maturation, differentiation, myelination, synaptogenesis

what enhances sprouting of axons and dendrites

stimulating environment

what does monocular deprivation during the vision critical period cause

ambylopia

three regions of the brain

forebrain, midbrain, hindbrain

what does spinal cord communicate with

muscles, sense organs

what does the spinal cord send to the brain

sensory info

what section of the spinal cord has the least amount of axons

sacral

what section of the spinal cord has the most amount of axons

cervical

why do axons go to the spinal cord

to reach efferent muscles