Input-specific bidirectional regulation of hippocampal CA3 pyramidal cell excitability.

ABSTRACT: High-frequency mossy fibre (MF) inputs trigger a sustained increase in excitability to perforant pathway (PP) inputs in CA3 pyramidal cells (CA3-PC) by reducing Kv1.2 levels at distal apical dendrites, known as long-term potentiation of intrinsic excitability (LTP-IE). LTP-IE enhances excitatory postsynaptic potential (EPSP)-to-spike coupling at PP synapses, facilitating Hebbian LTP of synaptic weights. Prolonged hyperexcitability is detrimental, yet it is little understood how LTP-IE is restored in CA3-PCs. Here we show that MF-induced LTP-IE can be reversed through the burst firing of a CA3-PC elicited by PP or recurrent synaptic inputs. This reversal was impeded by the oxidative bias of cellular redox state or intracellular Zn²⁺ signalling. Because high-frequency PP inputs to

SUBMITTER: Eom K 

PROVIDER: S-EPMC12320203 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature