Impaired Sprouting and Axonal Atrophy in Cerebellar Climbing Fibres following In Vivo Silencing of the Growth-Associated Protein GAP-43

The adult mammalian central nervous system has a limited ability to establish new connections and to recover from traumatic or degenerative events. The olivo-cerebellar network represents an excellent model to investigate neuroprotection and repair in the brain during adulthood, due to its high plasticity and ordered synaptic organization. To shed light on the molecular mechanisms involved in these events, we focused on the growth-associated protein GAP-43 (also known as B-50 or neuromodulin). During development, this protein plays a crucial role in growth and in branch formation of neurites, while in the adult it is only expressed in a few brain regions, including the inferior olive (IO) where climbing fibres (CFs) originate. Following axotomy GAP-43 is usually up-regulated in association with regeneration. Here we describe an in vivo lentiviral-mediated gene silencing approach, used for the first time in the olivo-cerebellar system, to efficiently and specifically downregulate GAP-43 in rodents CFs. We show that lack of GAP-43 causes an atrophy of the CF in non-traumatic conditions, consisting in a decrease of its length, branching and number of synaptic boutons. We also investigated CF regenerative ability by inducing a subtotal lesion of the IO. Noteworthy, surviving CFs lacking GAP-43 were largely unable to sprout on surrounding Purkinje cells. Collectively, our results demonstrate that GAP-43 is essential both to maintain CFs structure in non-traumatic condition and to promote sprouting after partial lesion of the IO

Prevenção e cuidados com a pele da criança e do recém-nascido Children and newborn skin care and prevention

A pele do neonato é submetida a um progressivo processo de adaptação ao ambiente extrauterino, para o qual cuidados especiais se tornam necessários. A sua pele caracteriza-se por ser sensível, fina e frágil. A imaturidade da sua barreira epidérmica diminui significativamente a defesa contra a excessiva proliferação microbiana, torna a pele mais susceptível ao trauma e à toxicidade por absorção percutânea de drogas. Devido às características próprias da pele do recém-nascido (RN), de lactentes e de crianças, o uso dos produtos cosméticos destinados à sua higiene e proteção requer um cuidado especial. Com o intuito de preservar a integridade da pele neonatal e infantil, este artigo revisou os cuidados preventivos básicos que se devem ter com a pele dos bebês quanto à higiene, ao banho, ao uso de agentes de limpeza, a produtos tópicos e a sua toxicidade percutânea.<br>Neonatal skin suffers a progressive adaptation to the extrauterine environment and special care is needed during this period. This skin is very sensitive, thin and fragile. Immaturity of the epidermal barrier reduces the defense against the excessive proliferation of microbes and makes the skin more vulnerable to trauma and percutaneous drug toxicity. Because of the peculiar characteristics of newborn, infant and children's skin, the use of cosmetic products designed for hygiene and protection requires caution. In order to preserve the integrity of neonatal and child's skin, this article reviewed basic preventive care practices in relation to hygiene, bathing, cleansing agents, topical products and their percutaneous toxicity