the nervous system (part 2-synapses) Flashcards
(49 cards)
the following process happens where: a signal transmission from a neuron to another neuron or another electrically excitable cell usually a muscle cell
synaptic cleft
the “speaker” that releases neurotransmitters into synapse
presynaptic cell
the “listener” binds neurotransmitters once they have diffused across the synapse
postsynaptic cell
what do synaptic vesicles carry
a specific amount of a single type of neurotransmitter (this makes them quantal)
when calcium enters the presynaptic neuron it binds to synaptotagmin which triggers movemnt of the vesicle toward the SNARE complexes where the vesicle will ______ with the cell membrane to release ________
fuse, neurotransmitters
in order for a chemical to be considered a neurotransmitter under Dale’s law it must…
1.) be present in presynaptic neuron, 2.) be released from presynaptic neuron in response to depolarization and 3.) be able to bind to specific receptors on the postsynaptic cell
what are the 2 types of neurotransmitters
excitatory and inhibitory
neurotransmitters that promote signal transmission between neurons, most common example is glutamate which is also the most abundant in the entire CNS
excitatory neurotransmitter
neurotransmitters that prevent signal transmission between neurons, most common example in the brain is GABA and most common in the spinal cord is glycine (released by interneurons)
inhibitory neurotransmitters
what is unique about GABA as a type of neurotransmitter
it is excitatory until around age 1 after birth due to dramatic changes in chloride concentrations
what are the different postsynaptic recpetor types
ionotropic and metabotropic
how do metabotropic receptors compare to ionotropic
they act slower and are usually GPCRs
this neurotransmitter typically is excitatory, is synthesized in the substantia nigra, and is involved in movement (voluntary and involuntary) and reward learning/motivation (addiction can be an implication too)
dopamine
this neurotransmitter typically produces excitatory response, signals via the dorsal and ventral attention networks and the salience network, mainly attributed to attention and is produced in the locus coeruleus
norepinephrine
this neurotransmitter is produced in the basal forebrain and is essential for long-term memory and arousal
acetylcholine
this neurotransmitter can be excitatory and inhibitory depending on the 5HT receptors it signals through, it is produced in the raphe nuclei in the brainstem and it is mostly associated with mood
serotonin
how are serotonin and melatonin related to seasonal affective disorder
they both use tryptophan so when its darker longer, more melatonin is produced thus using the tryptophan which leaves less for serotonin to be produced
we can categorize different types of plasticity into two broad groups:
hebbian plasticity and homeostatic plasticity
by applying a repeated tetanic stimulus to an individual neuron, one can observe the strengthening of this synapse corresponding to increased firing rate - this is…
long-term potentiation (LTP)
when an individual neuron is under-stimulated relative to baseline levels for a period of time resulting in weakening and decreased firing rate
long-term depression (LTD)
AMPA and NMDA receptors are the most abundant ionotropic glutamate receptors and for LTP to occur, signaling must happen through _____ receptor on the postynaptic neuron
NMDA
what are the 4 types of short-term plasticity (the period where neurons have refractory period between LTP and LTD to refresh their vesicles for further synaptic transmission)
facilitation-presynaptic
depression-presynaptic
saturation-postsynaptic
desensistization-postsynaptic
homeostatic plastcity is demonstrated best through
sleep
hebbian plasticity vs homeostatic plasticity feedback
positive feedback loop, negative feedback loop
