The brain that grows and develops under the continued influence of malnutrition presents permanent
impairment on functioning and neurotransmitter release. The aim of this study was to investigate the
chronic effects of neonatal food restriction on neurochemical and neurodynamical aspects within the
primary auditory sensory pathway. Our working hypothesis is that neonatal malnutrition may affect the flow
of primary sensory information both at a neurochemical and neurodynamical level. To test this hypothesis,
three groups of rats were assigned, from birth to 370 days of life, to the following dietary scheme: a wellnourished
(WN) group fed ad libitum lab chow diet; an undernourished (UN) group fed 60% of diet
consumed by WN group; and a rehabilitated group, undergoing same dietary restriction as
undernourished until 42 days of age and thereafter fed ad libitum until the end of the experiment. At 370
days of age, the animals were submitted to brainstem auditory-evoked potentials (BAEPs) recordings and
sacrificed for neurochemical evaluation of glutamate release. Undernutrition decreased glutamate release
in the cortex, hippocampus, midbrain and brainstem, and significantly increased the latency of BAEP
wave V. In addition; the re-establishment of the dietary conditions was not sufficient to reverse the
neurochemical and electrophysiological alterations observed in the UN group. Taken altogether, our
results suggest that malnutrition imposed at a critical development period caused an irreversible effect
within the auditory primary sensory pathway