Neuronal gap junctions: Expression, function, and implications for behavior

In this chapter, we will review what is currently known (and not known) about gap junction expression in neurons. We will discuss the composition of neuronal gap junctions, the functions of neuronal gap junctions acting as "electrical synapses," and attempt to highlight some of the many controversies surrounding these issues. The latter portion of this chapter will be devoted to modulation and plasticity of junctional communication between neurons, with a particular emphasis on the potential consequences of alterations in neuronal coupling for neural function and behavior. This chapter is not directed at those who are currently studying gap junction neurobiology per se, rather, it is an attempt to convince neuroscientists less familiar with the subject of the importance of direct intracellular communication between neurons in brain function. Often assumed to be static, we know now that gap-junctional communication is plastic and subject to modulation, and this plasticity is likely to have meaningful consequences for neural activity.