Correlation between morphological and biochemical effects of ethanol on neuroblast‐enriched cultures derived from three‐day‐old chick embryos

Abstract

We have shown that ethanol exposure during embryogenesis affects a variety of parameters of neuronal growth. In this study we examined the direct effects of ethanol exposure on developing neuroblasts in culture. Neuroblast-enriched cultures derived from 3-day-old whole chick embryos were grown in the presence of ethanol at doses ranging from 12.5 to 50 mM from culture day 3-14. Cholinergic and GABAergic phenotypic expression were both significantly reduced following ethanol exposure as assessed by the activities of choline acetyltransferase and glutamate decarboxylase, respectively. Morphometric analysis of the growth patterns showed significant differences between control and ethanol-treated cultures. Control cultures exhibited the characteristic pattern of growth consisting of neuronal aggregation with neuritic arborization, i.e., neuritic bundles and fasciculation. Cultures grown in ethanol from culture day 3 consisted of aggregates that measured significantly greater in size than those observed in control cultures. In addition, in ethanol-treated cultures, the primary pattern of neuritic bundles was replaced by a complex network of individual neurites radiating from the central aggregate, forming a defined "neuritic field." Morphometric analysis revealed that both neurite number and neurite length were significantly reduced in ethanol-treated cultures. The biochemical data confirm earlier reports from this laboratory suggesting that ethanol exposure during early embryogenesis alters the normal neuronal pattern of phenotypic expression. In addition, we have presented evidence in this study that ethanol alters the morphological growth patterns of developing neurons. Although ethanol does not alter the ability of these cells to aggregate, there is a significant alteration in neuritic outgrowth.(ABSTRACT TRUNCATED AT 250 WORDS)

The avian embryo as a model for fetal alcohol spectrum disorder

“…Like mammals, alcohol-exposed chick (6.3 mg as 40% alcohol directly atop the blastodisc) displays significant apoptosis in the early brain and spinal cord (E2), and this is accompanied by reduced proliferation and cell extrusions into the neural tube lumen (as per Sandor; Giles et al 2008). Neuronal migration is similarly impaired, and their neurite extensions are fewer, shorter, and more disorganized relative to the central body and adjacent cell layers (Dow and Riopelle 1985; Kentroti and Vernadakis 1991a; Quesada et al 1990). Using the classic chick spinal cord explant, Dow and Riopelle (1985) showed that alcohol muted neurite outgrowth in response to exogenous NGF (TD50 100–170 mg%); this was not due to impaired NGF binding but to reductions in neurotrophic factor production.…”

Maturation of cerebellar granule cells is delayed in cultures derived from ethanol‐treated chick embryos: Survival and proliferation studies

“…14,15,22,23,37,38 Moreover, we have found that exposure of chick embryos to ethanol during El-E3 affects differentially the expression of these neuronal phenotypes. 18,19,2° In addition, we have found that ethanol enhances programmed neuronal cell death. 2°, 33,34 In this study, we examined the effects of ethanol on a specific brain area, the cerebellum, during early neuroembryogenesis in the chick.…”

Ethanol neuronotoxicity in the embryonic chick brain in ovo and in culture: Interaction of the neural cell adhesion molecule (NCAM)

“…Previous studies from our laboratory have shown this to be an efficient method for maintaining cultures at a constant ethanol concentration. 19 The media was replaced once at 3 DIV and cultures re-treated with ethanol. At 4 DIV, ethanol-treated cultures were removed from the plastic bag and placed in the incubator to allow for evaporation of ethanol.…”

“…The effects of ethanol to alter the normal patterns of neuronal growth can readily be seen in culture, as we have previously demonstrated. 19,26 In order to establish a relationship between NCAM expression and the ethanol-induced alterations in morphology, we examined presence of NCAM immunoreactivity in neuroblast-enriched cultures grown in the absence or presence of ethanol. Results of this study demonstrated widespread immunoreactivity for NCAM on all neuronal elements including perikarya, neuritic processes and growth cones.…”