Building Blocks of the Nervous System

Neurons are the fundamental units of the nervous system, consisting of a cell body, dendrites, and an axon. Dendrites are antenna-like structures on the surface of the neuron that receive signals from other neurons, while axons transmit signals to subsequent neurons. The connection point between two neurons is referred to as a synapse. Information at the synapses is transmitted through the release of neurotransmitters that bind to receptors on the postsynaptic neuron. Synapses can either stimulate or inhibit the activity of the postsynaptic neuron. Learning is synonymous with experience-dependent changes in the connection structure of neural networks in the brain, known as neuroplasticity. Pruning, the removal of weak or unused synaptic connections between neurons, is a key mechanism for the development and refinement of neuronal circuits in the brain. Synaptic plasticity, i.e., the strengthening or weakening of synaptic connections between neurons, is another important type of neuroplasticity that encompasses various mechanisms. Homeostatic plasticity, including synaptic scaling and intrinsic plasticity, contributes to maintaining balance in the neural network. These processes ensure the efficiency of information processing in the brain. Glial cells make up more than half of the volume of neural tissue and play a crucial role in the central and peripheral nervous system by wrapping neurons with myelin, providing nutrients and oxygen, fighting pathogens, and eliminating dead neurons.