Local control of ventral subicular circuitry and its alteration by social isolation (360G-Wellcome-109005_Z_15_A)

The overall aim of this project is to use viral tracing, electrophysiology and optogenetics to investigate the local circuitry of the ventral subiculum (vS), and how this circuit is altered by social isolation stress – a common route to affective disorders such as depression and anxiety. I will first investigate the anatomical distribution of neurons in vS that project to the prefrontal cortex or the NAc. These have been shown to be distinct parallel populations with unique circuit functions, but very little is known about their detailed local circuit organisation. Next I will use optogenetics, electrophysiology and viral tracing to determine the functional connectivity of the local circuit that defines the differential activity of these projections. Despite strong hypotheses that local control is key in this circuit, how this is acheived mechanistically remains unknown. Finally, I will determine how this detailed projection-specific circuitry is altered by social isolation - a manipulation that drammatically alters vS circuitry - and aim to provide more specific targets for in vivo manipulations aimed at reversing isolation-induced behavioural deficits. Overall, these experiments will provide for the first time mechanistic insight into the function and organisation of vS circuitry, from individual synaptic connections, to circuit function.