Introducing Amyotrophic lateral sclerosis.

Introducing ALS at present times leads to re-define the concept of motor neuron selectivity which characterizes this disorder. In fact, multiple systems including skin, liver, and bone marrow are altered in ALS patients. The motor neuron is still the focus of the disorder and the extended pathology did not modify the concept of ALS as a devastating disorder based on motor neuron loss. Nonetheless, the involvement of non-motor neurons as well as areas outside the central nervous system leads to a different perspective to understand the causes, pathophysiology and therapy of ALS. For this reason a specific issue is dedicated to understand whether intersecting basic, pre-clinical and clinical knowledge of ALS may lead to a coherent novel scenario allowing to translate basic findings into clinical practice. Several pre-clinical issues described in this volume appear robust enough to indicate that we should modify a number of approaches when designing future therapeutic strategies. Similarly, novel investigations based on altered cell to cell communication are needed to further progress in understanding amyotrophic lateral sclerosis.