CNR - Institute of Neuroscience CNR
Institute of Neuroscience


Identification of the molecular mechanisms mediating environmental enrichment (EE) effects on retinal development

Environmental influence on visual system development and plasticity

The influence of environmental enrichment (EE) on the development and plasticity of the nervous system has been scarcely investigated. In the past few years, new evidence has been provided showing that EE has a remarkable impact on the developmental plasticity of the visual system. The most striking effect on visual system development elicited by an EE paradigm starting at birth is a marked acceleration in the maturation of visual cortical acuity (VA), a very sensitive and predictive index of visual system maturation (Cancedda et al. 2004).

Retinal acuity development is sensitive to environmental influence


We have recently begun to study the effects of the postnatal exposure to EE on the development and plasticity of retina. In particular we have shown by anatomical point of view that EE protracted for the whole pregnancy in the rat can modulate the temporal pattern of neural progenitor migration and cell death in the retinal ganglion cell layer (Sale et al., 2007). Furthermore, the dendritic stratification of ganglion cells during development (key feature for the emergence of ON and OFF visual pathways) is accelerated by EE (Landi et al. 2007b).A clear influence of EE on retinal development is also evident at functional level using pattern electroretinogram a sensitive measure of the function of retinal ganglion cells (RGCs), the final output of the entire retinal circuitry,. Recent data by Landi et al.(2007a) showed an accelerated development of retinal acuity maturation under the influence of EE.

Identification of molecular mechanisms mediating EE effects on retinal development


We are also able to identify the molecular pathways, activated by EE, involved in the retinal development . We demonstrated at functional level that insulin like growth factor (IGF-I) is the crucial mediator of the precocious maturation of retinal acuity, Indeed, administration of IGF-I in the first days of life leads to retinal acuity development. Conversely, blocking the action of IGF-1 during the same period completely prevents EE effects on retinal functional development. A particularly interesting result has been to clarify the mechanism downstream of IGF-1 triggered by EE. Very recent data showed that IGF-I action requires increased levels of BDNF and involves the maturation of the dopaminergic circuitry (Landi et. al., 2009).


  • Landi S, Ciucci F, Maffei L, Berardi N, Cenni MC (2009) Setting the pace for retinal development: environmental enrichment acts through insulin-like growth factor 1 and brain-derived neurotrophic factor. J. Neurosci. 29:10809-19.
  • Sale A, Cenni MC, Ciucci F, Putignano E, Chierzi S, Maffei L (2007) Maternal enrichment during pregnancy accelerates retinal development of the fetus. PLoS ONE 2:e1160.
  • Sale A, Maya Vetencourt JF, Medini P, Cenni MC, Baroncelli L, De Pasquale R, Maffei L (2007) Environmental enrichment in adulthood promotes amblyopia recovery through a reduction of intracortical inhibition. Nat. Neurosci. 10:679-81.
  • Landi S, Cenni MC, Maffei L, Berardi N (2007) Environmental enrichment effects on development of retinal ganglion cell dendritic stratification require retinal BDNF. PLoS ONE 2:e346.
  • Landi S, Sale A, Berardi N, Viegi A, Maffei L, Cenni MC (2007) Retinal functional development is sensitive to environmental enrichment: a role for BDNF. FASEB J. 21:130-9.


2009-2011 CARIPI Foundation (TRAIN THE BRAIN project), partner

2007-2009 RSTL CNR, partner

2007-2010 CHEM-PROFARMA-NET, partner



PI photo

Maria Cristina Cenni

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email  +39 050 3153162

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