More info in Omega 3 ( DHA and EPA)
Omega-3 Fatty Acids DHA and EPA May Be Linked to Ability to Process Sensory
Input
Abstracted by Susan Sweeny Johnson, PhD, Biochem, January 15, 2010, from
Irina Fedorova, Anita R. Alvheim, Nahed Hussein and Norman Salem Jr. Deficit
in Prepulse Inhibition in Mice Caused by Dietary n-3 Fatty Acid Deficiency.
Behavioral Neuroscience2009, Vol. 123, No. 6, 1218–1225.

KEY WORDS: DHA, omega-3 fatty acids, neuroprocessing

Omega-3 fatty acids found in dietary fats are basic components of cell
membranes and are crucial for cell function. Dietary α-linolenic acid (LNA
aka ALA) is found in plants and commonly ingested as flax seed oil.
Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are most commonly
ingested as fish oil. DHA is the most abundant omega-3 fatty acid in the
brain and plays an important role in learning and memory (1), and both DHA
and EPA provide benefits for the treatment of cardiovascular and
inflammatory diseases, and also in mood disorders (2-5). DHA incorporation
into brain cell membranes increases sensitivity to neural signals (6, 7) and
may regulate the production and usage of serotonin and dopamine, important
neurotransmitters in the brain (8).

Individuals with neuroprocessing diseases such as schizophrenia,
obsessive-compulsive disorder, Tourette’s syndrome, bipolar disorder, and
attention deficit disorder have a reduced ability to filter out background
sensory input as demonstrated by the standardized test called prepulse
inhibition of the acoustic startle reflex (PPI). The PPI test measures the
degree the subject is startled by a short high decibel auditory pulse with
and without a prior short, low decibel auditory pulse. The idea behind
prepulse inhibition is that sensory input is regulated by filtering out
irrelevant or distracting stimuli to prevent sensory information overload
and to allow for selective and efficient processing of only relevant
information (9).

In this new study, 48 pregnant mice were divided into four groups each fed a
diet rich in different omega-3 fatty acid:

Group 1: Omega-3 deficient diet, 0.07% of fatty acids as omega-3s
Group 2: Low ALA diet, 0.38% of fatty acids as ALA, no DHA/EPA
Group 3: High ALA diet, 4.76% of fatty acids as ALA, no DHA/EPA
Group 4: DHA + EPA diet, 1.98% of fatty acids as EPA, 2.05% as DHA and
0.38% as ALA

When the pups were born, they were fed the same diet as their mothers. At 8
weeks, one male pup from each litter was subjected to the PPI test and the
amount of DHA in its brains was measured.

No difference in health or development was observed for any of the test
subjects but the amount of DHA in the brain was different for each diet.
group 1 (omega-3 deficient diet) one showed an average 55% decrease compared
to group 4 (DHA/EPA diet). group 4 (DHA/EPA diet) had a 10% higher amount of
DHA in the brain as compared with group 3 (high ALA diet).

No difference in the startle response without a prepulse was observed for
all the subjects. However, when a prepulse was administered, the decrease in
startle response was highly dependent on diet. In groups 1 and 2, which had
low omega-3 diets, the reduction in the startle response by the prepulse was
50 + 5% less than that of group 4 (DHA/EPA diet) (p<0.001)*. In group 3
(high ALA diet), the reduction in startle response by the prepulse was about
25% less than that of group 4 (DHA/EPA diet) (p<0.001).

In addition, the ability to get used to the auditory startling sounds was
diminished significantly in groups 1 and 2 compared to groups 3 and 4. The
startle response was diminished about 20% after repeated tests for subjects
in groups 3 and 4 and four but was not reduced at all in groups 1 and 2.

These results suggest that diet during early development significantly
affects the ability to process sensory information and to learn from
previous stimuli. Deficiency in total dietary omega-3 fatty acids reduces
processing significantly and dietary DHA/EPA appears to be more beneficial
that ALA.

Further dietary studies with humans using the PPI test are suggested