Question: A researcher is interested in uncovering mechanisms of synaptic
transmission between two neurons….
A researcher is interested in uncovering mechanisms of synaptic
transmission between two neurons. To do this, she is studying
neurons cultured from embryonic mouse brain neural cells. The
researcher is interested in several aspects of neurotransmission
between neurons, but is particularly focused on the role of the
synapse in transmitting neuronal signals. Using the cultured
system, she is able to examine individual pairs of neurons that
communicate through chemical synapses, and modify different aspects
of the synaptic environment. She can decrease the extracellular
concentration of various ions and observe how this affects
neurotransmitter release and target cell behavior. She can also
apply a toxin that prevents synaptic vesicles from fusing with the
presynaptic membrane of axon terminals. Prior to these
manipulations, the researcher does a control experiment with two
neurons where she stimulates the presynaptic neuron to fire an
action potential and measures the response of the postsynaptic
neuron. Consistently, the postsynaptic neuron depolarizes and
propagates an excitatory potential.
Which neurotransmitter is most likely released based on
the results of the study described in the passage?
A. Glycine
B. Glutamate
C. GABA
D. Acetylcholine
