11/27: Neurotransmitters and Neuromuscular Control Flashcards
What are electrical synapses?
Two neurons connected by a gap junction
What do electrical synapses allow for?
Electrical current to flow directly from one cell to the other
What are chemical synapses?
Release of neurotransmitters from axon terminal (presynapatic membrane) and bind to receptors on postsynaptic membrane
What trigger EPSPs/IPSPs or modulate the postsynaptic cell?
Neurotransmitters
What is the amount of neurotransmitter packaged in the terminal?
Quanta
Once a neurotransmitter has bound to its receptor on the postsynaptic vesicle, what does it trigger?
EPSPs and IPSPs
What are EPSPs?
Excitatory postsynaptic potentials
What are IPSPs?
Inhibitory postsynaptic potentials
What are responsible for starting the process of binding vesicles to synaptic membrane?
SNARE proteins
Where are SNARE proteins found?
In the SV and plasma membrane
What do SNARE proteins do?
Help dock vesicles and then zip together to force membranes to fuse
What triggers fusion and exocytosis?
Calcium
Depending on the NT and the type of receptor it binds to, it can ______ or ______ the postsynaptic membrane
Excite; inhibit
What are excitatory neurotransmitters?
Glutamate
Aspartate
Nitric oxide
What are inhibitory neurotransmitters?
Glycine
GABA
Serotonin
Dopamine
What are both inhibitory and excitatory neurotransmitters?
Acetylcholine
Norepinephrine
What is an example of an EPSP summation?
NT opens cation channels for Na+ or Ca2+
What is an example of IPSP summation?
NT opens Cl- channels
What do neurons receive inputs from?
Other neurons synapsing with the dendrites or cell body
Where do the sums of all the EPSPs and IPSPs occur within a neuron?
Axon hillox
What happens when the graded potential caused by the summation of EPSPs/IPSPs reach a threshold potential at the axon hillock?
Opens a voltage gated Na+ channel and induces an action potential in the neuronal axon
What are small molecule transmitters?
Acetylcholine
ATP/adenosine
What are the three amino acid derivative small molecule neurotransmitters?
Glutamate (Glu)
Gamma-amminobutyric acid (GABA)
Glycine (Gly)
What are the 5 amine based small molecule neurotransmitters?
- Serotonin (5-HT)
- Histamine
- Dopamine (DA)
- Norepinephrine (NE)
- Epinephrine (E)
What small molecule neurotransmitter is excitatory?
Glutamate
What small molecule neurotransitter is inhibitory?
GABA
What neurotransmitters are released by the hypothalamus?
Thyrotropin-releasing hormone, leutenizing hormone releasing hormone somatosatin
What neurotransmitters are released by the pituitary?
Adrenocrticotropic hormone
Prolactin
Luteinizing hormone
Thyrotropin
Growth hormone
Vasopressin
Oxytocin
What are examples of endorphins?
Enkephalins
Opioids
What are other types of proteins/peptide neurotransmitters?
Substance P
Bradykinin
Angiotensin II