The coordinating role of the brain and its network of nerves, previously assigned by Aristotle to the heart and the vessels, wasn’t admitted until the 18th century. The “leadership” of the brain was definitely established by Gall and Broca during the 19th century, but during the 20th century another organ that doesn’t “think” but “senses” has emerged as a “brilliant second,” leading to the concept of neuronal skin.
An important neuroendocrine activity was discovered in this organ, with the local production of many neurotransmitters. While recent progress in neurobiology has generated new pharmaceutical approaches for the treatment of neuropathies, neuromuscular diseases and neuropsychiatric disorders, we can now consider the opportunities for cosmetic products. The Skin’s Nervous System
Neurons are fragile cells with low regenerative potential. Therefore neuroprotection qualifies as a special application for skin care. Benefits of neuroprotection are not limited to improved or preserved sensory functions. Maintenance of the skin’s neuroendocrine activity, which is involved in many biological processes, is needed for global preservation of skin homeostasis. Effective protection requires specific approaches that take into account the particular survival mechanisms of neurons.
Consistent with its sensory function, skin is highly innervated. Many sensitive fibers reach the most superficial living layers of the epidermis. Therefore, cosmetic ingredients can easily access this exposed nervous system (no blood/brain barrier, here). They may have psycho sensorial effects by activating superficial nervous endings, but the generation of pleasant feelings is difficult to achieve due to extreme variability in individual perception.
Excerpt Only This is a shortened version or summary of the article that appeared in the July 1, 2003 issue of Cosmetics & Toiletries magazine. The full content is not currently available online.