The brain is an organ with a complex structure and is composed of various types of cells. It is mainly composed of neurons and glia cells, and a higher brain function results from the formation of complex neuronal networks. What is the best way to understand the brain? One way is by understanding how molecular and cellular mechanisms are formed. Among them, it is important to know the molecular mechanisms by which neuronal networks are developed, a process initiated during early cell-cell interactions.
In addition, it is essential to understand the mechanism of signal transduction inside the cells during network formation at various developmental stages and also in the mature brain. The functions of the brain are multiple and complex – it is a centrally regulating organizing system of multiple simultaneous functions. As we begin to understand it, we recognize the specific functions and specific role individual cells have to perform, and the interactions of the cells that are needed for such functions. The understanding of these cell to cell interactions, which involve intracellular changes, is essential for understanding the multiple role of the brain, and also for understanding any change responsible for malfunction of this organ.
This volume of the Handbook of Neurochemistry and Molecular Neurobiology is a collection of chapters that describe the ‘‘Neural Signaling Mechanism’’ of the brain. The first chapters briefly cover the molecular mechanisms occurring during the development of the nervous system: genesis, migration and differentiation of neurons and neuronal positioning, cell fate determination involved in the regulation of axonal formation, and neural process formation. Subsequently, the signaling mechanism in synaptic transmission is described; a key process of neural function is the way neurons influence one another through synaptic contacts.