Nervous System 2 Flashcards
(43 cards)
Involves neurotransmitters (NT) that are released from the presynaptic cell and bind receptors to excite, inhibit, or modify post-synaptic cell.•>100 NT have been identified. •One-way conduction
Chemical synapses
Is it the receptor or the NT that determines the function?
Receptor
The ______ receptor subtypes are the largest known neurotransmitter-receptor family
5-Hydroxytryptamine (5-HT)/Serotonin
_____ synapses terminate on neuronal cell bodies and tend to be inhibitory.
Axosomatic synapses
_____ synapses terminate on dendrites or dendritic spines and tend to be excitatory.
Axodendritic synapses
_____ synapses terminate on an axon, often close to synaptic terminals, and modulate the release of neurotransmitters.
Axoaxonal synapses
The amount of ____ that enters dictates the amount of NT released
Ca
Which synapse moderate the amount of Ca coming into the cell?
Axoaxonal synapse
There is Synaptic delay of at least _____ between the pre-synaptic depolarization and post-synaptic response Due to time for calcium entry for exocytosis, presynaptic neurotransmitter release, diffusion in the synaptic cleft, and postsynaptic receptor activation
0.5ms
_____ Allows one to gauge the complexity of a reflex pathway (number of synapses) by looking at the speed of the reflex.
Synaptic delay
_____ NTs are rapidly-acting –Elicit acute responses. –Final processing occurs in the axon terminal. Vesicles are docked & ready for release from presynaptic terminal. –Ex: Acetylcholine, Norepinephrine, Dopamine, Serotonin (5-HT), Histamine, Glycine, GABA, Glutamate, Nitric Oxide (NO).
Small molecules,
_____ NTs are larger molecules, slower–Effects are slower, more potent, & more prolonged.–Produced in the cell body and transported down the axon via axonal streaming. –Fewer neuropeptides produced and released–Ex: LH, ACTH, GH, vasopressin, oxytocin, angiotensin II, substance P
Neuropeptides
_______ is terminated by: •Re-uptake by the pre-synaptic membrane (6), •Absorption by glial cells (8)•Inactivation by enzymes in the synapse
NT action
_____ receptors directly affect ion channels
Ionotropic Receptors
____ receptors are G-protein coupled receptors
Metabotropic Receptors
____ are due to•Opening Na+ channels•Closing K+ and/or Cl- channels
EPSPs
____ are due to•Opening Cl- channels•Increased K+ conductance
IPSPs
____ is almost always necessary to produce an AP
Summation of EPSPs
Postsynaptic potentials last up to _____ msec
15 msec
____ summation is simultaneous EPSPs or IPSPs from multiple pre-synaptic neurons; added in space
Spatial summation
_____ summation is successive EPSPs or IPSPs from a single presynaptic nerve terminal; added in time
Temporal summation
When an inhibitory interneuron (red) releases an inhibitory transmitter (ex. GABA) on a postsynaptic neuron. This produces an ____ that decreases the potential of the postsynaptic neuron from reaching threshold.
IPSP
When an excitatory interneuron (green) releases an excitatory transmitter (ex. Glutamate) on a postsynaptic neuron. This produces an ___ that increases the potential of the postsynaptic neuron from reaching threshold
EPSP
Pre-synaptic inhibition and facilitation is due to ____ synapses
Axo-Axonic Synapses
