Dissecting Neuronal Circuits: Analysis of Basket Cell-like Interneurons in Cortical Layer 6

To understand how neuronal circuits underlie the processing of brain function, methods must be employed to dissect the circuit. Identification of the neuronal subtypes and characterization of how they interact are required to effectivity gain insight into understanding the neuronal circuit. The method to decipher neuronal circuits I describe and use here is the simultaneous multiple patch-clamp recording system. My overall aim was to elucidate interneuronal circuits in cortical layer 6 (L6), which are critical for specific brain processes such regulating sensory information. Studies on the connectivity of L6 have predominately focused on excitatory pyramidal neurons. Relatively little is known of the subtypes of GABAergic interneurons in L6 and how they are incorporated into the circuit. However, the role of L6 GABAergic inhibitory interneurons in brain function has recently become more appreciated.
In this dissertation, I first provide background on L6 and basket cells, the most abundant GABAergic interneuron subtype. Then, in Chapters 2 and 3, I describe the simultaneous multiple patch-clamp recording system that is used to decipher interneuronal circuits. In Chapter 4, I examine a population of L6 interneurons using this method. Finally, I discuss my results and the field moving forward.