Attachment-Based Learning And Bdnf Gene Expression In The Infant Rat Olfactory Bulb
Date
2016-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
Infant-caregiver experiences are known to impact neurobiological and
behavioral development. The olfactory and tactile sensory systems are crucial to infant
rats’ survival, as they are born blind and deaf. Maternal attachment-based olfactory
learning allows for vital behaviors such as orientation to the mother and nipple
attachment. Learning occurs throughout development and requires the interaction of
the environment and brain, suggesting epigenetic regulation in the brain as a possible
mechanism. The brain structures required for olfactory learning prior to postnatal day
10 include the olfactory bulb (OB), locus coeruleus, and anterior piriform cortex.
Brain-derived neurotrophic factor (bdnf) is a gene crucial to neuroplasticity, learning,
and memory. Environmentally induced epigenetic modifications such as DNA
methylation of bdnf result in altered levels of transcription and may lead to altered
bdnf gene expression in the OB following odor learning. In this study we employ an
odor-stroke conditioning paradigm to promote attraction to peppermint odor. When
stroking was paired with presentation of peppermint odor, pups demonstrated an
attachment-based preference for peppermint odor 24 hours post-conditioning. This
learning paralleled increased expression of bdnf mRNA in the OB 30 minutes postconditioning.
Taken together, these data provide evidence that maternal attachmentbased
associative learning in the sensitive period rat affects bdnf gene expression in
the OB. Future studies will determine whether this reflects experience-dependent
epigenetic regulation of bdnf.
Description
Keywords
gene expression, attachment-based learning, neuroscience