chapter 5 Flashcards
gap junctions
where electrical synapses occur. interconnect non neural cells like smooth cardiac muscle, liver and glia
connexins
proteins that make up gap junction
connexon
made from 6 connexin sub units
how many connexons form a gap junction channel
2
difference between electrical and chemical synapse
electrical are faster
pore of gap junction is larger
electrical synapse is bidirectional
step after incoming signal depolarizes membrane above threshold, travels down axon and then reaches the axon terminal
synaptic transmission
synapse
a specialized junction where one part of a neuron contacts and communicates with another neuron or cell type
what does it mean to be electrically coupled
cells that are connected by a gap junction
in electrical synapses, can the first neuron have a PSP induced by the second?
yes, they are bidirectional
where are electrical synapses often found in the brain
where normal function requires that the activity of neighboring neurons is highly synced
inferior olive
neurons in brain step nucleus that can generate small oscillations of membrane voltage and action potentials. they send axons to cerebellum and are important in motor control
when are gap junctions prominent?
early in development. it helps with growth and maturation
synaptic cleft
what pre and post synaptic membranes are separated by in chemical synapse
what is the synaptic cleft filled with?
extracellular protein. it serves as a “glue” that binds membranes together
what is usually the presynaptic element
axon terminal
synaptic vesicle
stores neurotransmitters
secretory granule
larger vesicles that contain soluble protein. also called dense-core vesicle since it appears dark
membrane differentiations
accumulation of protein adjacent to and within membranes on EITHER SIDE of synaptic cleft
active zones
actual sites of NT release
where are synaptic vesicles clustered?
cytoplasm adjacent to active zone
post synaptic density
protein thickly accumulated in and under postsynaptic membrane. contains NT receptors
what do neurotransmitter receptors do?
convert intercellular chemical signal to an intracellular chemical signal
if a post synaptic membrane is a dendrite
axodendritic
is a postsynaptic membrane is a cell body
axosomatic