Long-term potentiation (LTP), one of the most widely studied forms of neuronal plasticity, has been amply documented in excitatory synapses on pyramidal neurons. However, there is scant evidence for this phenomenon in inhibitory interneurons.
Using perforated-patch recordings, Lamsa et al. elicited robust Hebbian-type LTP in hippocampal stratum radiatum interneurons. This pathway-specific LTP does not require dendritic spines and depends on disynaptic feedforward inhibition of pyramidal cells. If memory encoding mediated by LTP were to enhance only monosynaptic excitation and not disynaptic inhibition of pyramidal neurons, this would degrade the fidelity of information processing. However, the temporal fidelity of synaptic integration and action potential generation can be preserved if LTP also occurs in feedforward interneurons. â PRS
Nat. Neurosci. 8, 916 (2005).