PT  - JOURNAL ARTICLE
AU  - Hernández-Vivanco, Alicia
AU  - Jiménez-Redondo, Esther
AU  - Cano-Adamuz, Nuria
AU  - Méndez, Pablo
TI  - Protein Kinase A-Dependent Plasticity of Local Inhibitory Synapses from Hilar Somatostatin-Expressing Neurons
AID  - 10.1523/ENEURO.0089-23.2023
DP  - 2023 Oct 01
TA  - eneuro
PG  - ENEURO.0089-23.2023
VI  - 10
IP  - 10
4099  - http://www.eneuro.org/content/10/10/ENEURO.0089-23.2023.short
4100  - http://www.eneuro.org/content/10/10/ENEURO.0089-23.2023.full
SO  - eNeuro2023 Oct 01; 10
AB  - Hippocampal inhibitory neurons (INs) contact local targets and project to different brain areas to form synapses on distal neurons. Despite the importance of INs for hippocampal function and interregional brain communication, the impact of activity-dependent plasticity mechanisms on local and long-range GABAergic synapses formed by hippocampal INs remains to be fully elucidated. Here, we use optogenetic-coupled electrophysiology in mice to show that protein kinase A (PKA), a master regulator of GABAergic synapse plasticity, causes a form of long-term potentiation of inhibitory synapses (iLTP) in hippocampal granule cells (GCs). This form of iLTP is observed in GCs synapses originated in local INs expressing the marker somatostatin (SST), but not in those expressing parvalbumin. Long-range synapses formed by SST INs onto medial septum neurons are unaffected by PKA activation. iLTP of local SST synapses on GCs is accompanied by changes in presynaptic probability of release and is occluded by pharmacological increase of synaptic activity in vivo. Our results suggest that PKA-dependent inhibitory synapse plasticity is expressed in local, but not long-range, targets of SST INs and selectively modifies inhibitory microcircuits essential for hippocampal function.