JoVE Encyclopedia of Experiments
Neuroscience
0 views • 2:47 min • August 7th, 2025
Begin with a rat surgically implanted with optical fibers targeting the synapses between neurons of the medial geniculate nucleus (MGN) and the lateral amygdala (LA) .
The rat is conditioned to press a lever to receive a narcotic through a catheter, an action associated with auditory and visual cues.
During repeated conditioning, the auditory signals travel via the MGN and induce upregulation of neurotransmitter receptors at the synapses, strengthening the synaptic connections.
The virally transduced rat expresses light-sensitive ion channels in the MGN neurons.
Deliver low-frequency pulses via the optical fibers to open these channels, a process called optogenetic stimulation.
The resulting cation influx induces low-frequency neurotransmitter release.
The neurotransmitters bind to receptors on LA neurons and induce a low-level calcium influx, which induces neurotransmitter receptor internalization and weakens the synapses.
The weakened MGN-LA synaptic transmission leads to diminished neuronal communication, known as long-term depression (LTD), and reduces cue-associated narcotic-seeking behavior.
For optogenetic induction of long-term depression or LTD, connect patch cables to a 473 nano
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