The presubiculum is part of the parahippocampal region and it contains neurons that are sensitive to head direction. These head direction cells provide crucial input to entorhinal grid cells and they are important for hippocampal-based landmark navigation.  In my talk, I will focus on the physiology and anatomy of single presubicular neurons. Using optogenetic tools, paired records and responses to head direction signals of the intact animal, we provide new detail on how dynamic properties of inhibitory circuits sculpt head direction information processing in presubiculum.  We show that presubicular pyramidal cells and parvalbumin expressing interneurons are directly excited by thalamic input.  Martinotti type interneurons are indirectly recruited by local pyramidal neurons in a facilitating manner, and their inhibitory feedback plays a dual role: precisely timed spikes may not inhibit the firing of in-tune head direction cells, while exerting lateral inhibition.
References
Nat Commun. 2017; 8:16032
https://www.nature.com/articles/ncomms16032

Front Neural Circuits. 2015; 9:20
http://journal.frontiersin.org/article/10.3389/fncir.2015.00020/full