**3. Axonal degeneration**

Communication from cell bodies to the peripheral spines happens due to the neuronal axon. Various insults may compromise this communication and deteriorate the neuronal axons: trauma, blockade of neuronal transport, or chemical toxicity. The normal trauma associated to axonal degeneration is nerve injury or some stroke. Protein involved in axonal transport deficit or accumulation of protein may also contribute to the axonal degeneration Correale et al., 2019.

excitatory, and for this reason different effects are observed in neuron functionality. Mutation or alteration of neurotransmitters affects receptor functionality and neurodegenerative effect.

Introductory Chapter: A Common Feature of Neurodegenerative Disorders

http://dx.doi.org/10.5772/intechopen.84132

3

Epigenetic mechanism affects cell activity and functionality. Recently, some papers demonstrate a functional role of microRNA in regulation of gene expression. The alteration of microRNA machinery alters gene expression and affects neuronal function Dardiotis E et al.,

Activation of inflammatory pathway generates a neuronal cascade molecule activation following the external stimuli. The inflammatory pathway is also responsible of synaptic pruning with the elimination of immature and nonactive spines. When this system is altered, many

The study of different molecular pathways of synaptic plasticity is one of the most intriguing mechanism to identify how neuronal works and intervene in neurodegenerative cases. Most of the neuronal diseases are linked to the neurodegeneration. For this reason, the study of this mechanism is essentially important in the field of neuroscience and is necessary to intervene

**8. microRNA**

2018; wang xh et al., 2018.

**9. Probably microglia and inflammation**

in case of pathology Paasila pj et al., 2019.

**Author details**

Antonella Borreca

of neuronal activities are affected and neurodegeneration occurs.

Address all correspondence to: antonella.borreca@gmail.com

CNR-National Research Council, Institute of Cell Biology and Neurobiology, Italy
