BACKGROUND: Early life adverse experience alters adult emotional and cognitive development. Here we assess early life learning about adverse experience and its consequences on adult fear conditioning and amygdala activity. METHODS: Neonatal rats were conditioned daily from 8-12 days-old with paired odor (conditioned stimulus, CS) .5mA shock, unpaired, odor-only, or naive (no infant conditioning). In adulthood, each infant training group was divided into three adult training groups: paired, unpaired or odor-only, using either the same infant CS odor, or a novel adult CS odor without or with the infant CS present as context. Adults were cue tested for freezing (odor in novel environment), with amygdala (14)C 2-DG autoradiography and electrophysiology assessment. RESULTS: Infant paired odor-shock conditioning attenuated adult fear conditioning, but only if the same infant CS odor was used. The (14)C 2-DG activity correlated with infant paired odor-shock conditioning produced attenuated amygdala but heightened olfactory bulb activity. Electrophysiological amygdala assessment further suggests early experience causes changes in amygdala processing as revealed by increased paired-pulse facilitation in adulthood. CONCLUSIONS: This suggests some enduring effects of early life adversity (shock) are under CS control and dependent upon learning for their impact on later adult fear learning.
BACKGROUND: Early life adverse experience alters adult emotional and cognitive development. Here we assess early life learning about adverse experience and its consequences on adult fear conditioning and amygdala activity. METHODS: Neonatal rats were conditioned daily from 8-12 days-old with paired odor (conditioned stimulus, CS) .5mA shock, unpaired, odor-only, or naive (no infant conditioning). In adulthood, each infant training group was divided into three adult training groups: paired, unpaired or odor-only, using either the same infant CS odor, or a novel adult CS odor without or with the infant CS present as context. Adults were cue tested for freezing (odor in novel environment), with amygdala (14)C 2-DG autoradiography and electrophysiology assessment. RESULTS: Infant paired odor-shock conditioning attenuated adult fear conditioning, but only if the same infant CS odor was used. The (14)C 2-DG activity correlated with infant paired odor-shock conditioning produced attenuated amygdala but heightened olfactory bulb activity. Electrophysiological amygdala assessment further suggests early experience causes changes in amygdala processing as revealed by increased paired-pulse facilitation in adulthood. CONCLUSIONS: This suggests some enduring effects of early life adversity (shock) are under CS control and dependent upon learning for their impact on later adult fear learning.
Authors: Millie Rincón-Cortés; Gordon A Barr; Anne Marie Mouly; Kiseko Shionoya; Bestina S Nuñez; Regina M Sullivan Journal: Proc Natl Acad Sci U S A Date: 2015-01-05 Impact factor: 11.205
Authors: Stephanie Moriceau; Charlis Raineki; Jennifer D Holman; Jason G Holman; Regina M Sullivan Journal: Front Behav Neurosci Date: 2009-09-01 Impact factor: 3.558