Adolescent behavior and dopamine availability are uniquely sensitive to dietary omega-3 fatty acid deficiency

Background—Understanding the nature of environmental factors that contribute to behavioralhealth is critical for successful prevention strategies in individuals at-risk for psychiatric disorders.These factors are typically experiential in nature, such as stress and urbanicity, but nutrition, inparticular dietary deficiency of omega-3 polyunsaturated fatty acids (n-3 PUFAs), has increasinglybeen implicated in the symptomatic onset of schizophrenia and mood disorders, which typicallyoccurs during adolescence to early adulthood. Thus, adolescence may be the critical age range forthe negative impact of diet as an environmental insult.Methods—A rat model involving consecutive generations of n-3 PUFA deficiency wasdeveloped based on the assumption that dietary trends toward decreased consumption of these fatsbegan four-five decades ago when the parents of current adolescents were born. Behavioralperformance in a wide range of tasks, as well as markers of dopamine-related neurotransmissionwas compared in adolescents and adults fed n-3 PUFA adequate and deficient diets.Results—In adolescents, dietary n-3 PUFA deficiency across consecutive generations produceda modality-selective and task-dependent impairment in cognitive and motivated behavior distinctfrom the deficits observed in adults. While this dietary deficiency affected expression ofdopamine-related proteins in both age groups, in adolescents, but not adults, there was an increasein tyrosine hydroxylase expression that was selective to the dorsal striatum.Conclusions—These data support a nutritional contribution to optimal cognitive and affectivefunctioning in adolescents. Furthermore, they suggest that n-3 PUFA deficiency disruptsadolescent behaviors through enhanced dorsal striatal dopamine availability.