A critical period for omega-3 nutritional supplementation in the development of the rodent visual system.
Retinocollicular connections form precise topographical maps that are normally completed through the selective elimination of misplaced axons and the stabilization of topographically ordered axon terminals during early development. Omega-3 fatty acids, acquired exclusively through the diet, and its main metabolite, docosahexaenoic acid (DHA), are involved in brain development and synaptic maturation. We have previously shown that the nutritional restriction of omega-3/DHA results in abnormal retinocollicular topographical fine-tuning. Therefore, we studied the role of omega-3 fatty acids nutritional supplementation and the developmental time windows during which this postnatal supplementation would restore normal topographical maps in the visual system. Female rats and their litters were chronically fed with either control (soy oil) or restricted omega-3 (coconut oil) diets. Fish oil supplementation was introduced between either postnatal day (PND) 7-13, PND7-28 or PND21-42. At PND13, PND28 or PND42, animals received an anterograde eye injection of a neuronal tracer to visualize retinocollicular axons. Confirming previous observations we found that an omega-3/DHA deficiency resulted in an abnormally high innervation density of retinal axons at the visual layers of the superior colliculus (SC). Although a short-term fish oil supplementation between PND7-13 could not restore normal retinocollicular topography, an extended treatment between PND7-28 completely recovered normal innervation densities of retinotectal axons. However, a late onset supplementation protocol, between PND28-42, was no longer effective in the restoration of the abnormal topographical pattern induced by an early omega-3 nutritional malnutrition. The results suggest a critical period for omega3/DHA dietary intake for the proper development of visual topographical maps.
Departamento de Neurobiologia, Universidade Federal Fluminense, Niterói, Brazil; Instituto de Nutrição Josué de Castro, Universidade Federal do Rio de Janeiro, Brazil.
P C
PC
De Velasco
Departamento de Neurobiologia, Universidade Federal Fluminense, Niterói, Brazil.
P C
PC
Sandre
Instituto de Nutrição Josué de Castro, Universidade Federal do Rio de Janeiro, Brazil.
M G
MG
Tavares Do Carmo
Departamento de Neurobiologia, Universidade Federal Fluminense, Niterói, Brazil.
A C
AC
Faria-Melibeu
Departamento de Neurobiologia, Universidade Federal Fluminense, Niterói, Brazil.
P
P
Campello-Costa
Departamento de Fisiologia, Universidade Federal do Paraná, Curitiba, Curitiba, Brazil.
A C
AC
Ferraz
Departamento de Fisiologia, Universidade Federal de Pernambuco, Recife, Brazil.
B L S
BLS
Andrade Da Costa
Departamento de Neurobiologia, Universidade Federal Fluminense, Niterói, Brazil. Electronic address: claudio.serfaty@gmail.com.
C A
CA
Serfaty
D000818:Animals; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000008:administration & dosage; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D051381:Rats; D012160:Retina / Q000166:cytology / Q000254:growth & development*; D013477:Superior Colliculi / Q000166:cytology / Q000254:growth & development*; D013997:Time Factors; D014795:Visual Pathways / Q000254:growth & development*
D015525:Fatty Acids, Omega-3; D004281:Docosahexaenoic Acids
Critical period; Development; Docosahexaenoic acid; Essential fatty acids; Nutrition; Plasticity; Retinotectal; Topographical maps; Visual acuity; Visual system