Understanding the nervous system as an information processing machine

This thesis is the combination of two separate lines of work linked by one common goal: understanding the nervous system as an information-processing machine. David Marr (1982) put forth the idea that in order to fully understand an information-processing machine one must understand it at three separate levels. The computational goal of the system must be understood separately from the algorithm by which it is computed and the hardware in which it is computed. During my time as a graduate student I have been fortunate enough to work on two different levels in two very different systems. Chapter 1 focuses on the hardware of neural circuitry, specifically on how inhibitory interneurons connect to excitatory neurons. Chapter 2 focuses on the algorithmic problem of how flies could use gyroscopic sensors to calculate angular velocity.