Journal article
Basolateral Amygdala Inputs to the Medial Entorhinal Cortex Selectively Modulate the Consolidation of Spatial and Contextual Learning
The Journal of neuroscience, Vol.38(11), pp.2698-2712
03/14/2018
DOI: 10.1523/JNEUROSCI.2848-17.2018
PMCID: PMC5852655
PMID: 29431646
Abstract
Although evidence suggests that the basolateral amygdala (BLA) and dorsal hippocampus (DH) work together to influence the consolidation of spatial/contextual learning, the circuit mechanism by which the BLA selectively modulates spatial/contextual memory consolidation is not clear. The medial entorhinal cortex (mEC) is a critical region in the hippocampus-based system for processing spatial information. As an efferent target of the BLA, the mEC is a candidate by which the BLA influences the consolidation of such learning. To address several questions regarding this issue, male Sprague Dawley rats received optogenetic manipulations of different BLA afferents immediately after training in different learning tasks. Optogenetic stimulation of the BLA–mEC pathway using ChR2(E123A) after spatial and cued-response Barnes maze training enhanced and impaired retention, respectively, whereas optical inhibition of the pathway using eNpHR3.0 produced trends in the opposite direction. Similar stimulation of the BLA-posterior dorsal striatum pathway had no effect. BLA–mEC stimulation also selectively enhanced retention for the contextual, but not foot shock, component of a modified contextual fear-conditioning procedure. In both sets of experiments, only stimulation using bursts of 8 Hz light pulses significantly enhanced retention, suggesting the importance of driving activity in this frequency range. An 8 Hz stimulation of the BLA–mEC pathway increased local field potential power in the same frequency range in the mEC and in the DH. Together, the present findings suggest that the BLA modulates the consolidation of spatial/contextual memory via projections to the mEC and that activity within the 8 Hz range is critical for this modulation.
SIGNIFICANCE STATEMENT
The mechanism by which the basolateral amygdala (BLA) influences the consolidation of spatial/contextual memory is unknown. Using an optogenetic approach with multiple behavioral procedures, we found that immediate posttraining 8 Hz stimulation of BLA projections to the medial entorhinal cortex (mEC) enhanced retention for spatial/contextual memory, impaired retention for cued-response memory, and had no effect on foot shock learning for contextual fear conditioning. Electrophysiological recordings confirmed that 8 Hz stimulation of this pathway increased activity in the 8 Hz range in the mEC and in the dorsal hippocampus, a region critical for spatial memory consolidation. This suggests that coordinated BLA activity with downstream regions in the 8 Hz activity range immediately after training is important for consolidation of multiple memory forms.
Details
- Title: Subtitle
- Basolateral Amygdala Inputs to the Medial Entorhinal Cortex Selectively Modulate the Consolidation of Spatial and Contextual Learning
- Creators
- Krista L Wahlstrom - Department of Psychological and Brain SciencesMary L Huff - Department of Psychological and Brain SciencesEric B Emmons - Interdisciplinary Graduate Program in NeuroscienceJohn H Freeman - Department of Psychological and Brain SciencesNandakumar S Narayanan - Iowa Neuroscience InstituteChrista K McIntyre - School of Behavioral and Brain Sciences, University of Texas–Dallas, Richardson, Texas 75080Ryan T LaLumiere - Department of Psychological and Brain Sciences
- Resource Type
- Journal article
- Publication Details
- The Journal of neuroscience, Vol.38(11), pp.2698-2712
- Publisher
- Society for Neuroscience
- DOI
- 10.1523/JNEUROSCI.2848-17.2018
- PMID
- 29431646
- PMCID
- PMC5852655
- ISSN
- 0270-6474
- eISSN
- 1529-2401
- Language
- English
- Date published
- 03/14/2018
- Academic Unit
- Neurology; Psychological and Brain Sciences; Iowa Neuroscience Institute
- Record Identifier
- 9984065862502771
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