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Zhang XQ, Xu L, Yang SY, Hu LB, Dong FY, Sun BG, Shen HW. Reduced Synaptic Transmission and Intrinsic Excitability of a Subtype of Pyramidal Neurons in the Medial Prefrontal Cortex in a Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2021; 84:129-140. [PMID: 34487044 DOI: 10.3233/jad-210585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Abnormal morphology and function of neurons in the prefrontal cortex (PFC) are associated with cognitive deficits in rodent models of Alzheimer's disease (AD), particularly in cortical layer-5 pyramidal neurons that integrate inputs from different sources and project outputs to cortical or subcortical structures. Pyramidal neurons in layer-5 of the PFC can be classified as two subtypes depending on the inducibility of prominent hyperpolarization-activated cation currents (h-current). However, the differences in the neurophysiological alterations between these two subtypes in rodent models of AD remain poorly understood. OBJECTIVE To investigate the neurophysiological alterations between two subtypes of pyramidal neurons in hAPP-J20 mice, a transgenic model for early onset AD. METHODS The synaptic transmission and intrinsic excitability of pyramidal neurons were investigated using whole-cell patch recordings. The morphological complexity of pyramidal neurons was detected by biocytin labelling and subsequent Sholl analysis. RESULTS We found reduced synaptic transmission and intrinsic excitability of the prominent h-current (PH) cells but not the non-PH cells in hAPP-J20 mice. Furthermore, the function of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels which mediated h-current was disrupted in the PH cells of hAPP-J20 mice. Sholl analysis revealed that PH cells had less dendritic intersections in hAPP-J20 mice comparing to control mice, implying that a lower morphological complexity might contribute to the reduced neuronal activity. CONCLUSION These results suggest that the PH cells in the medial PFC may be more vulnerable to degeneration in hAPP-J20 mice and play a sustainable role in frontal dysfunction in AD.
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Affiliation(s)
- Xiao-Qin Zhang
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China.,Key Laboratory of Addiction Research of Zhejiang Province, Ningbo Kangning Hospital, Ningbo, Zhejiang, China
| | - Le Xu
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Si-Yu Yang
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Lin-Bo Hu
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Fei-Yuan Dong
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Bing-Gui Sun
- Department of Neurobiology, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Hao-Wei Shen
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China.,Key Laboratory of Addiction Research of Zhejiang Province, Ningbo Kangning Hospital, Ningbo, Zhejiang, China
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Yamamuro K, Yoshino H, Ogawa Y, Makinodan M, Toritsuka M, Yamashita M, Corfas G, Kishimoto T. Social Isolation During the Critical Period Reduces Synaptic and Intrinsic Excitability of a Subtype of Pyramidal Cell in Mouse Prefrontal Cortex. Cereb Cortex 2019; 28:998-1010. [PMID: 28158488 DOI: 10.1093/cercor/bhx010] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Indexed: 12/11/2022] Open
Abstract
Juvenile social experience is crucial for the functional development of forebrain regions, especially the prefrontal cortex (PFC). We previously reported that social isolation for 2 weeks after weaning induces prefrontal cortex dysfunction and hypomyelination. However, the effect of social isolation on physiological properties of PFC neuronal circuit remained unknown. Since hypomyelination due to isolation is prominent in deep-layer of medial PFC (mPFC), we focused on 2 types of Layer-5 pyramidal cells in the mPFC: prominent h-current (PH) cells and nonprominent h-current (non-PH) cells. We found that a 2-week social isolation after weaning leads to a specific deterioration in action potential properties and reduction in excitatory synaptic inputs in PH cells. The effects of social isolation on PH cells, which involve reduction in functional glutamatergic synapses and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/N-methyl-d-aspartate charge ratio, are specific to the 2 weeks after weaning and to the mPFC. We conclude that juvenile social experience plays crucial roles in the functional development in a subtype of Layer-5 pyramidal cells in the mPFC. Since these neurons project to subcortical structures, a deficit in social experience during the critical period may result in immature neural circuitry between mPFC and subcortical targets.
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Affiliation(s)
- Kazuhiko Yamamuro
- Department of Psychiatry, Nara Medical University, Kashihara, Nara 634-8522, Japan
| | - Hiroki Yoshino
- Department of Psychiatry, Nara Medical University, Kashihara, Nara 634-8522, Japan
| | - Yoichi Ogawa
- Department of Physiology I, Nara Medical University, Kashihara, Nara 634-8522, Japan
| | - Manabu Makinodan
- Department of Psychiatry, Nara Medical University, Kashihara, Nara 634-8522, Japan
| | - Michihiro Toritsuka
- Department of Psychiatry, Nara Medical University, Kashihara, Nara 634-8522, Japan
| | - Masayuki Yamashita
- Center for Medical Science, International University of Health and Welfare, Ohtawara, Tochigi 324-8501, Japan
| | - Gabriel Corfas
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Toshifumi Kishimoto
- Department of Psychiatry, Nara Medical University, Kashihara, Nara 634-8522, Japan
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