Abstract
The central nucleus of the amygdala (CeA) is a brain region implicated in anxiety, stress-related disorders and the reinforcing effects of drugs of abuse. Corticotropin-releasing factor (CRF, Crh) acting at cognate type 1 receptors (CRF1, Crhr1) modulates inhibitory and excitatory synaptic transmission in the CeA. Here, we used CRF1:GFP reporter mice to characterize the morphological, neurochemical and electrophysiological properties of CRF1-expressing (CRF1+) and CRF1-non-expressing (CRF1–) neurons in the CeA. We assessed these two neuronal populations for distinctions in the expression of GABAergic subpopulation markers and neuropeptides, dendritic spine density and morphology, and excitatory transmission. We observed that CeA CRF1+ neurons are GABAe-rgic but do not segregate with calbindin (CB), calretinin (CR), parvalbumin (PV), or protein kinase C-δ (PKCδ). Among the neuropeptides analyzed, Penk and Sst had the highest percentage of co-expression with Crhr1 in both the medial and lateral CeA subdivisions. Additionally, CeA CRF1+ neurons had a lower density of dendritic spines, which was offset by a higher proportion of mature spines compared to neighboring CRF1– neurons. Accordingly, there was no difference in basal spontaneous glutamatergic transmission between the two populations. Application of CRF increased overall vesicular glutamate release onto both CRF1+ and CRF1– neurons and does not affect amplitude or kinetics of EPSCs in either population. These novel data highlight important differences in the neurochemical make-up and morphology of CRF1+ compared to CRF1– neurons, which may have important implications for the transduction of CRF signaling in the CeA.
Original language | English (US) |
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Article number | e0087-19.2019 |
Journal | eNeuro |
Volume | 6 |
Issue number | 3 |
DOIs | |
State | Published - 2019 |
Funding
This work was supported by the Pearson Center for Alcoholism and Addiction Research and by National Institute on Alcohol Abuse and Alcoholism/National Institutes of Health Grants AA021491, AA015566, AA006420, AA017447, AA026685, AA024952, F32: AA026865, T32: AA007456, and U01 AA013498. *S.A.W., H.S., R.R.P., C.C., and M.R. These authors contributed equally. Acknowledgements: We thank Dr. Nick Justice for providing CRF1:GFP breeders. This is manuscript number 29813 from The Scripps Research Institute. Correspondence should be addressed to M. Roberto at mroberto@ scripps.edu. https://doi.org/10.1523/ENEURO.0087-19.2019 Copyright © 2019 Wolfe et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license, which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
Keywords
- Calcium binding proteins
- Corticotropin-releasing factor
- Dendritic spines
- Glutamatergic signaling
- Neuropeptides
- Stress and anxiety
ASJC Scopus subject areas
- General Neuroscience