Question

Induction of LTP in mammals and short-term enhancement of the gill withdrawal reflex (sensitization) in Aplysia are similar in that both are dependent upon?

1) activation of serotonin receptors
2) activation of protein kinases
3) activation of the NMDA receptor
4) activation of G protein-linked receptors

Answer 1

Both the induction of Long-term Potentiation (LTP) in mammals and the sensitization in Aplysia depend on the activation of protein kinases, which are part of a cellular cascade triggered by calcium influx through NMDA receptors.

Step-by-step explanation:

The induction of Long-term Potentiation (LTP) in mammals and the short-term enhancement of the gill withdrawal reflex in Aplysia share a common dependency on the activation of protein kinases. When the postsynaptic neuron is depolarized by multiple presynaptic inputs, the NMDA (N-Methyl-D-aspartate) receptors allow for the influx of Ca2+ ions, initiating a signaling cascade that involves the activation of protein kinases such as CaMKII. These protein kinases, in turn, phosphorylate various targets including some AMPA receptors, enhancing the strength of the synaptic connection and potentially leading to LTP.

While serotonin receptors are involved in the sensitization of Aplysia by increasing the number of synaptic connections, it is the downstream activation of protein kinases triggered by the calcium influx through NMDA receptors that is the shared mechanism between the induction of LTP and the sensitization observed in Aplysia. Thus, option 2) activation of protein kinases is the correct answer.