What is different about activities on the two sides of the synapse?
What is different about activities on the two
sides of the synapse (axon next to muscle or
dendrite of other nerve)?
SALMAN UL ISLAM
o Nerve Cell
o Transmission across the synapse----- Neuromuscular
o Neuron-----electrically excitable cell-----processing and
transmitting information through electrical and chemical
o Neurons communicate with each other by synaptic
o Synapses transmit, process, and store information in
Courtesy of the Südhof lab. See Südhof, T.C. 2008. Nature 455:903-911 for details.
Three parts of a nerve cell are:
o dendrites: branches that receive sensory input and
bring it to the neuron’s cell body;
o cell body: contains the nucleus, mitochondria, and
ribosomes. The cell body carries on the normal metabolic
cellular functions of the nerve cell.
o axon: a long fiber extending from the cell body. The role
of the axon is to transmit a nerve impulse to another cell.
Parts of a Nerve cell
The presynaptic cell ends in an axon terminal that contains
calcium channels and synaptic vesicles with
The postsynaptic cell has ion channels with receptors for
Between the two cells is a small gap called the synaptic
Transmission across the synapse-----
Neuromuscular junction (NMJ)
o “ The place where the motor neuron makes a functional
contact with the skeletal muscle cell is called
NEUROMUSCULAR JUNCTION or MYONEURAL
The synapse is a connection between a neuron and its
target cell (which is not necessarily a neuron).
The presynaptic element is the synaptic end bulb of the
axon where Ca2+ enters the bulb to cause vesicle fusion
and neurotransmitter release.
The neurotransmitter diffuses across the synaptic cleft to
bind to its receptor.
Resulting action potential leads to muscle contraction.
The neurotransmitter is cleared from the synapse either
by enzymatic degradation or neuronal reuptake.