| 1. |
- Barr, Gordon A, et al.
(author)
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Transitions in infant learning are modulated by dopamine in the amygdala
- 2009
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In: Nature Neuroscience. - : Nature Publishing Group. - 1097-6256 .- 1546-1726. ; 12, s. 1367-1369
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Journal article (peer-reviewed)abstract
- Behavioral transitions characterize development. Young infant rats paradoxically prefer odors that are paired with shock, but older pups learn aversions. This transition is amygdala and corticosterone dependent. Using microarrays and microdialysis, we found downregulated dopaminergic presynaptic function in the amygdala with preference learning. Corticosterone-injected 8-d-old pups and untreated 12-d-old pups learned aversions and had dopaminergic upregulation in the amygdala. Dopamine injection into the amygdala changed preferences to aversions, whereas dopamine antagonism reinstated preference learning.
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| 2. |
- Moriceau, Stephanie, et al.
(author)
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Concurrent Neonatal Activation Of The Amygdala-fear Circuit And The Attachment Circuit During Infancy
- 2007
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Conference paper (peer-reviewed)abstract
- Infant altricial species learn to prefer stimuli paired with pain, presumably due to the importance of learning to prefer the caregiver regardless of the qual ity of care. This attenuated avoidance/fear learning appears due to low corticosterone (CORT), which keeps the amygdala ‘‘dormant’’. Indeed, simply increasing CORT permits amygdala plasticity and fear conditioning. Here we assess whether CORT also activates the locus coeruleus (LC) and increases NE via amygdala CRF efferents to the LC. In all experiments, PN7–8 pups received 11 pairings of odor-0.5 mA shock and were tested the next day for an odor preference/aversion (Y-maze). 14C 2-DG was used for neural assessment during conditioning. In Experiment 1, we found that the CORT induced odor aversion was correlated with olfactory bulb activation. Since this neural change is usually dependent upon increased NE and limited to neonates, we next assessed the pathway from the amygdala to the LC. In Experiment 2, we directly infused CORT into the lateral amygdala that activates the CRF efferents to the LC and an odor aversion was again obtained. In Experiment 3, we infused CRF directly into the LC, which produced an odor aversion and an increase in olfactory bulb NE (microdialysis). Pups with control LC vehicle infusions continued to acquire the age characteristic shock-induced odor preference. These results suggested that early activation of the amygdala dependent fear system can be precociously induce in neonates, although this is done in concert with the neonatal NE olfactory bulb learning system. [RMS Funding NSF IBN0117234, NICHD HD33402, OCAST]
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| 3. |
- Moriceau, Stephanie, et al.
(author)
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Early-Life Stress Disrupts Attachment Learning : The Role of Amygdala Corticosterone, Locus Ceruleus Corticotropin Releasing Hormone, and Olfactory Bulb Norepinephrine
- 2009
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In: Journal of Neuroscience. - Washington, United States : Society for Neuroscience. - 0270-6474 .- 1529-2401. ; 29:50, s. 15745-15755
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Journal article (peer-reviewed)abstract
- Infant rats require maternal odor learning to guide pups’ proximity-seeking of the mother and nursing. Maternal odor learning occurs using a simple learning circuit including robust olfactory bulb norepinephrine (NE), release from the locus ceruleus (LC), and amygdala suppression by low corticosterone (CORT). Early-life stress increases NE but also CORT, and we questioned whether early-life stress disrupted attachment learning and its neural correlates [2-deoxyglucose (2-DG) autoradiography]. Neonatal rats were normally reared or stressed-reared during the first 6 d of life by providing the mother with insufficient bedding for nest building and were odor–0.5 mA shock conditioned at 7 d old. Normally reared paired pups exhibited typical odor approach learning and associated olfactory bulb enhanced 2-DG uptake. However, stressed-reared pups showed odor avoidance learning and both olfactory bulb and amygdala 2-DG uptake enhancement. Furthermore, stressed-reared pups had elevated CORT levels, and systemic CORT antagonist injection reestablished the age-appropriate odor-preference learning, enhanced olfactory bulb, and attenuated amygdala 2-DG. We also assessed the neural mechanism for stressed-reared pups’ abnormal behavior in a more controlled environment by injecting normally reared pups with CORT. This was sufficient to produce odor aversion, as well as dual amygdala and olfactory bulb enhanced 2-DG uptake. Moreover, we assessed a unique cascade of neural events for the aberrant effects of stress rearing: the amygdala–LC–olfactory bulb pathway. Intra-amygdala CORT or intra-LC corticotropin releasing hormone (CRH) infusion supported aversion learning with intra-LC CRH infusion associated with increased olfactory bulb NE (microdialysis). These results suggest that early-life stress disturbs attachment behavior via a unique cascade of events (amygdala–LC–olfactory bulb).
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| 4. |
- Shionoya, Kiseko, 1964-, et al.
(author)
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Development switch in neural circuitry underlying odor-malaise learning
- 2006
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In: Learning & memory (Cold Spring Harbor, N.Y.). - : Cold Spring Harbor Laboratory Press (CSHL). - 1072-0502 .- 1549-5485. ; 13:6, s. 801-808
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Journal article (peer-reviewed)abstract
- Fetal and infant rats can learn to avoid odors paired with illness before development of brain areas supporting this learning in adults, suggesting an alternate learning circuit. Here we begin to document the transition from the infant to adult neural circuit underlying odor-malaise avoidance learning using LiCl (0.3 M; 1% of body weight, ip) and a 30-min peppermint-odor exposure. Conditioning groups included: Paired odor-LiCl, Paired odor-LiCl-Nursing, LiCl, and odor-saline. Results showed that Paired LiCl-odor conditioning induced a learned odor aversion in postnatal day (PN) 7, 12, and 23 pups. Odor-LiCl Paired Nursing induced a learned odor preference in PN7 and PN12 pups but blocked learning in PN23 pups. 14C 2-deoxyglucose (2-DG) autoradiography indicated enhanced olfactory bulb activity in PN7 and PN12 pups with odor preference and avoidance learning. The odor aversion in weanling aged (PN23) pups resulted in enhanced amygdala activity in Paired odor-LiCl pups, but not if they were nursing. Thus, the neural circuit supporting malaise-induced aversions changes over development, indicating that similar infant and adult-learned behaviors may have distinct neural circuits.
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| 5. |
- Shionoya, Kiseko, 1964-, et al.
(author)
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Maternal attenuation of hypothalamic paraventricular nucleus norepinephrine switches avoidance learning to preference learning in preweanling rat pups
- 2007
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In: Hormones and Behavior. - : Elsevier. - 0018-506X .- 1095-6867. ; 52:3, s. 391-400
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Journal article (peer-reviewed)abstract
- Infant rats learn to prefer stimuli paired with pain, presumably due to the importance of learning to prefer the caregiver to receive protection and food. With maturity, a more ‘adult-like’ learning system emerges that includes the amygdala and avoidance/fear learning. The attachment and ‘adult-like’ systems appear to co-exist in older pups with maternal presence engaging the attachment system by lowering corticosterone (CORT). Specifically, odor–shock conditioning (11 odor–0.5 mA shock trials) in 12-day-old pups results in an odor aversion, although an odor preference is learned if the mother is present during conditioning. Here, we propose a mechanism to explain pups ability to ‘switch’ between the dual learning systems by exploring the effect of maternal presence on hypothalamic paraventricular nucleus (PVN) neural activity, norepinephrine (NE) levels and learning. Maternal presence attenuates both PVN neural activity and PVN NE levels during odor–shock conditioning. Intra-PVN NE receptor antagonist infusion blocked the odor aversion learning with maternal absence, while intra-PVN NE receptor agonist infusion permitted odor aversion learning with maternal presence. These data suggest maternal control over pup learning acts through attenuation of PVN NE to reduce the CORT required for pup odor aversion learning. Moreover, these data also represent pups’ continued maternal dependence for nursing, while enabling aversion learning outside the nest to prepare for pups future independent living.
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| 6. |
- Sullivan, Regina M., et al.
(author)
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Developmental Neurobiology of Olfactory Preference and Avoidance Learning
- 2014
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In: Oxford Handbook of Developmental Behavioral Neuroscience. - Oxford : Oxford University Press. - 9780195314731 ; , s. 573-587
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Book chapter (other academic/artistic)abstract
- Infants from a myriad of species attach to their caregiver regardless of the quality of care received, although the quality of care influences development of the stress system. To better understand this relationship, this chapter characterizes attachment learning and the supporting neural circuit in infant rat pups. During early life, odors paired with pain paradoxically produce subsequent approach responses to the odor and attachment. The neural circuit supporting this attachment learning involves the olfactory bulb encoding the preference learning and suppression of the amygdala to prevent the aversion learning. Increasing the stress hormone corticosterone during acquisition or decreasing endogenous opioids during consolidation prevents this odor approach learning. These data suggest that early life attachment is readily learned and supported by both increased opioids and decreased stress.
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