Question

how is a synapse formed?

class 11th....biology ​

Answer 1

Answer:

Synapse formation begins as soon as axons contact their targets, and entails the extensive transformation of presynaptic axonal terminals and postsynaptic dendritic processes into specialized structures that allow the efficient transmission of signals across an extracellular space. This chapter follows the entire process of synapse formation, including the molecular mechanisms that allow the pre- and postsynaptic processes to stick to together and organize the subcellular machinery of the synapse. We follow the formation of different types of excitatory and inhibitory synapses, consider the role of glial cells as helpers in this process, and discuss the plasticity of synapses and how their functional properties change with time.

Synapse formation involves recognition of specific postsynaptic targets by growing axons, formation of initial contacts, and subsequent elaboration of the transmitter release machinery and the postsynaptic apparatus at contact sites. Defasciculation of axons in the target areas, their branching and establishing of contacts with postsynaptic cells are tightly coordinated in time and space by expression of diverse attractive and repellent recognition molecules. Further stabilization of contacts involves coordinated exchange by anterograde and retrograde signals between pre- and postsynaptic elements. The formation of synaptic contacts is accomplished by accumulation of synaptic vesicles and proteins engaged in depolarization-dependent exo- and endocytocis of vesicles in the presynaptic active zones aligned via transsynaptic adhesive interactions with postsynaptic clusters of transmitter receptors, channels, and intracellular signaling molecules.