Fig. 5: PV-iLTD and SST-iLTP mechanisms.

a Illustration of PV-iLTD mechanism. Hyperpolarisation by GABAA receptor currents relieves T-type VGCCs from voltage dependent inactivation (de-inactivation). Back-propagating action potentials then activate T-type VGCCs providing an inhibitory synapse-specific source of Ca2+ to activate calcineurin resulting in LTD at PV synapses. b Illustration of SST-iLTP mechanism. Similar to PV-iLTD but requiring activation of T-type and L-type VGCCs that activates CAMKII resulting in LTP at SST synapses.