Dysregulation of ErbB4 Signaling Pathway in the Dorsal Hippocampus after Neonatal Hypoxia-Ischemia and Late Deficits in PV+ Interneurons, Synaptic Plasticity and Working Memory.

Publication Type Academic Article
Authors Spahic H, Parmar P, Miller S, Emerson P, Lechner C, St Pierre M, Rastogi N, Nugent M, Duck S, Kirkwood A, Chavez-Valdez R
Journal Int J Mol Sci
Volume 24
Issue 1
Date Published 12/28/2022
ISSN 1422-0067
Keywords Memory, Short-Term, Parvalbumins, Receptor, ErbB-4
Abstract Neonatal hypoxic-ischemic (HI) injury leads to deficits in hippocampal parvalbumin (PV)+ interneurons (INs) and working memory. Therapeutic hypothermia (TH) does not prevent these deficits. ErbB4 supports maturation and maintenance of PV+ IN. Thus, we hypothesized that neonatal HI leads to persistent deficits in PV+ INs, working memory and synaptic plasticity associated with ErbB4 dysregulation despite TH. P10 HI-injured mice were randomized to normothermia (NT, 36 °C) or TH (31 °C) for 4 h and compared to sham. Hippocampi were studied for α-fodrin, glial fibrillary acidic protein (GFAP), and neuroregulin (Nrg) 1 levels; erb-b2 receptor tyrosine kinase 4 (ErbB4)/ Ak strain transforming (Akt) activation; and PV, synaptotagmin (Syt) 2, vesicular-glutamate transporter (VGlut) 2, Nrg1, and ErbB4 expression in coronal sections. Extracellular field potentials and behavioral testing were performed. At P40, deficits in PV+ INs correlated with impaired memory and coincided with blunted long-term depression (LTD), heightened long-term potentiation (LTP) and increased Vglut2/Syt2 ratio, supporting excitatory-inhibitory (E/I) imbalance. Hippocampal Nrg1 levels were increased in the hippocampus 24 h after neonatal HI, delaying the decline documented in shams. Paradoxically ErbB4 activation decreased 24 h and again 30 days after HI. Neonatal HI leads to persistent deficits in hippocampal PV+ INs, memory, and synaptic plasticity. While acute decreased ErbB4 activation supports impaired maturation and survival after HI, late deficit reemergence may impair PV+ INs maintenance after HI.
DOI 10.3390/ijms24010508
PubMed ID 36613949
PubMed Central ID PMC9820818
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