Question

In a typical long-term potentiation (LTP) study, a stimulating electrode is inserted into the perforant path, while a recording electrode is inserted into the dentate gyrus. LTP is produced in this preparation by delivering a(n) ________ via the stimulating electrode.

a.single high-intensity electrical pulse
b. single low-intensity electrical pulse
c.electrical pulse every minute for 2-3 hours
d. long-duration but low-intensity pulse
e. burst of 100 electrical pulses in a few seconds.

Answer 1

LTP in the brain is induced by a burst of 100 electrical pulses in a few seconds, leading to the inclusion of more AMPA receptors in the postsynaptic membrane, strengthening the synaptic connection.

Step-by-step explanation:

In a typical study of long-term potentiation (LTP), the stimulation required to produce LTP via a stimulating electrode placed in the perforant path is e. a burst of 100 electrical pulses in a few seconds. This high-frequency burst of stimuli leads to a sustained rise in the postsynaptic cell's calcium levels. This calcium influx, passing mainly through NMDA receptors which are relieved of their magnesium ion block following depolarization, triggers a cascade that ultimately results in the incorporation of more AMPA receptors into the postsynaptic neuron's membrane. This incorporation of AMPA receptors strengthens the synapse and consequently increases the likelihood that the postsynaptic neuron will fire in response to subsequent glutamate release from the presynaptic neuron. LTP and its counterpart, long-term depression (LTD), are mechanisms crucial for synaptic plasticity, which refers to the strengthening or weakening of synapses, and play significant roles in learning and memory.