Essential fatty acid deficiency reduces cortical spreading depression propagation in rats: a two-generation study.

Cortical spreading depression (CSD) propagation was investigated in rats under dietary essential fatty acid (EFA) deficiency over two generations (F1 and F2). Wistar rat dams received diets containing 5% fat either from coconut-oil (EFA-deficient) or soybean-oil (control). F1-pups received their dams' diets until the day of CSD recording (30-40 days or 90-100 days). F2-pups were kept on their F1 dams' diet until 30-40 days. Compared to the controls, the EFA-deficient group had reduced (P < 0.05) body weights in both F1 and F2 conditions. This effect was more conspicuous (P < 0.001) in the F2-animals where brain weight was also reduced (P < 0.05). All EFA-deficient groups displayed lower CSD velocities (P < 0.001) than the corresponding controls. Within the same dietary group and generation, F1 young rats showed higher CSD velocities (P < 0.001) than adults. Data show that EFA deficiency reduces CSD propagation, and this effect is long lasting as it persists up to the second generation.

Dopaminergic cell populations of the rat substantia nigra are differentially affected by essential fatty acid dietary restriction over two generations.

Essential fatty acids play a crucial role in the activity of several neurotransmission systems, especially in the monoaminergic systems involved in cognitive and motor aspects of behavior. The present study investigated whether essential fatty acid dietary restriction over two generations could differentially affect dopaminergic cell populations located in the substantia nigra rostro-dorso-medial (SNrm) or caudo-ventro-lateral (SNcv) regions which display distinct neurochemical profile and vulnerability to lesions under selected pathological conditions. Wistar rats were raised from conception on control or experimental diets containing adequate or reduced levels of linoleic and α-linolenic fatty acids, respectively. Stereological methods were used to estimate both the number and soma size of tyrosine hydroxylase (TH)-immunoreactive neurons in the SNrm and SNcv. TH protein levels were assessed with Western blots. Long-term treatment with the experimental diet modified the fatty acid profile of midbrain phospholipids and significantly decreased TH protein levels in the ventral midbrain (3 fold), the number of TH-positive cells in the SNrm (∼20%) and the soma size of these neurons in both SNrm (∼20%) and SNcv (∼10%). The results demonstrate for the first time a differential sensitivity of two substantia nigra dopaminergic cell populations to unbalanced levels of essential fatty acids, indicating a higher vulnerability of SNrm to the harmful effects induced by docosahexaenoic acid brain deficiency.