The vertebrate central nervous system has evolved into a specialized organ responsible for higher cognitive and functional behaviors. Fast, reliable, stereotyped relays of messages from one neuron to the next is responsible for both intrinsic homeostatic functions such as breathing, to much ofthe responses necessary for adaptation and higher neuronal functioning. The concept of neurotransmission was revolutionized in the second half ofthe nineteenth century by the seminal work ofthe neuroanatomist, Santiago Ramon Y Cajal. Using new stains for microscopy and impeccable observational skills, Cajal was the first neurobiol-ogist expanding the cell theory, introduced by Schleiden and Schwann in the 1830s, to suggest that the nervous system was a collection of diverse cellular entities that communicated with each other through noncontinuous connections. These connections were termed synapses by Charles Sherington in 1897, after the Greek word for" clasp"[1]. Thus the neuron doctrine, which holds that the nervous system is comprised of individual cells, termed neurons, gained fervor in thescientific community. Cajal's belief was in contrast to the one popularized by his famous contemporary, Camillo Golgi, whose reticularist model contended that the nervous system was one big syncycium of interconnected parts with a directly communicating protoplasm [1]. In fact, the neuron doctrine has been unequivocally supported by rigorous experimentation, with the ultimate proof provided by electron microscopic studies ofthe synapse by George Palade and others in the mid-1950s [1-3]. Interestingly, it has been determined that certain few neurons directly communicate through specialized intercytoplasmic junctions, termed gap junctions, which allow for bi-directional flow of ions and small signaling molecules [1, 4-6]. The function ofthese electrical synapses, however, is mainly thought to be the synchronization of activity within certain groups of neurons [1, 7, 8].