title: Tactile stimulation during development alters the neuroanatomical organization of the optic nerve in normal rats.
abstract: This study was designed to investigate the progressive effect of tactile stimulation in the cytoarchitecture of the optic nerve of normal rats during early postnatal development. We used 36 male pups which were randomly assigned to either the tactile-stimulated group (TS-stimulation for 3 min, once a day, from postnatal day (P) 1 to 32) or the non-tactile-stimulated (NTS) group. Morphological analysis were performed to evaluate the alterations caused by tactile stimulation, and morphometric analysis were carried out to determine whether the observed changes in optic nerve cytoarchitecture were significantly different between groups and at three different ages (P18, P22, and P32), thereby covering the entire progression of development of the optic nerve from its start to its completion. The rats of both groups presented similar increase in body weight. The morphometric analysis revealed no difference in the astrocyte density between age-matched groups; however, the oligodendrocyte density of TS group was higher compared to the NTS at P22, and P32, but not at P18. The optic nerve of TS group showed an increase of blood vessels and a reduction of damage fiber density when compared to the age-matched pups of NTS. Taken together, these findings support the view that tactile stimulation, an enriching experience, can positively affects the neuroanatomy of the brain, modifying its cellular components by progressive morphological and morphometric changes.
authors.affiliation: Department of Psychology, Faculty of Philosophy, Sciences and Letters of Ribeirao Preto, University of Sao Paulo, São Paulo, Brazil.|Laboratory of Neuroanatomy, Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes 3900, Ribeirão Prêto, São Paulo, 14049-900, Brazil.
authors.forename: Everton
authors.initials: E
authors.lastname: Horiquini-Barbosa
authors.affiliation: Laboratory of Neuroanatomy, Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes 3900, Ribeirão Prêto, São Paulo, 14049-900, Brazil. jjlachat@fmrp.usp.br.
authors.forename: João-José
authors.initials: JJ
authors.lastname: Lachat
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D008297:Male; D009900:Optic Nerve / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology; D010812:Physical Stimulation; D051381:Rats; D017208:Rats, Wistar; D014110:Touch / Q000502:physiology*
keywords: Brain development; Morphological analysis; Morphometric analysis; Optic nerve; Tactile stimulation