Long-term potentiation (LTP) is a phenomenon of formation or strengthening of new synapses with repeated stimulation of excitatory-neurons. It is the underlying mechanism of long-term memory. Long-term depression (LTD) occurs due to the repeated low-frequency stimulation.
In experimental studies, similar to LTP and LTD, LTPi and LTDi are found on the gamma-amino butyric acid (GABA) neurons, which are the inhibitory neurons.
Thus, the blank can be filled with GABAergic.