Long chain polyunsaturated fatty acids (PUFAs), particularly arachidonic acid and docosahexaenoic acid (DHA), are integral components of neural membrane phospholipids. DHA deficiency is associated with behavioural and neurophysiological disorders. A deficiency of DHA markedly affects neurotransmission, membrane-bound proteins, ion channel activities and synaptic plasticity, and the supplementation restores neurotransmission. Although the molecular mechanism of DHA involvement remains unknown, more and more data demonstrate its implication in various cellular activities contributing to regulation of neurotransmission. Since recent studies have provided evidence that n-3 deficiency altered neurogenesis in embryonic brain, the question of lasting effects on neural function can be addressed.