-We have studied the morphological an d quantitative aspects of the myenteric plexus neurons of the proximal colon in rats (Rattus norvegicus of Wistar strain) submitted to a protein deprivation during prenatal and lactatio n periods . Twent y pregnan t dam s wer e divide d i n fou r group s labele d accordin g t o th e kin d o f nourishment they were given: Group NN, normal diet; Group DN, low protein diet during prenatal period, and normal diet during lactation period; Group ND, normal diet during prenatal period, and low protein diet during lactation period ; Group DD, low protein die t during prenatal an d lactation periods. Histological analyses wer e developed wit h proxima l colo n segment s usin g th e haematoxyli n an d eosi n stainin g method . Membran e preparations were stained by Giemsa's method. The statistical analysis has demonstrated no significant differenc e among the mean s o f neuron s foun d i n th e fou r studie d groups . I t was notice d tha t th e animal s unde r protei n deprivation durin g prenata l an d lactatio n period s presente d greate r quantit y o f larg e an d strongl y basophili c myenteric neurons. This suggest s that neurons have accumulated protei n i n the cytoplasm .KEY WORDS: enteric neurons, myenteric plexus, proteic deprivation, proximal colon, gestation, lactation.Reviewing the available data, it was found that many authors direct their studies to the effec t of undernutrition o n the central nervous system 3,16,18,19 . Fe w were the studies foun d relatin g t o the effects of undernutrition on the peripheral nervous system, and fewer were the studies found concerning