Impaired neuronal macroautophagy in the prelimbic cortex contributes to comorbid anxiety-like behaviors in rats with chronic neuropathic pain.

ABSTRACT

A large proportion of patients with chronic pain experience co-morbid anxiety. The medial prefrontal cortex (mPFC) is proposed to underlie this comorbidity, but the molecular and neuronal mechanisms are not fully understood. Here, we reported that impaired neuronal macroautophagy in the prelimbic cortical (PrL) subregion of the mPFC paralleled the occurrence of anxiety-like behaviors in rats with chronic spared nerve injury (SNI). Intriguingly, such macroautophagy impairment was mainly observed in a FOS/c-Fos+ neuronal subpopulation in the PrL. Chemogenetic inactivation of this comorbid anxiety-related neuronal ensemble relieved pain-induced anxiety-like behaviors. Rescuing macroautophagy impairment in this neuronal ensemble relieved chronic pain-associated anxiety and mechanical allodynia and restored synaptic homeostasis at the molecular level. By contrast, artificial disruption of macroautophagy induced early-onset co-morbid anxiety in neuropathic rats, but not general anxiety in normal rats. Taken together, our work identifies causal linkage between PrL neuronal macroautophagy dysfunction and comorbid anxiety in neuropathic pain and provides novel insights into the role of PrL by differentiating its contribution in pain-induced comorbid anxiety from its modulation over general anxiety-like behaviors.Abbreviation AAV adeno-associated viruses; ACC anterior cingulate cortex; ATG5 autophagy related 5; ATG7 autophagy related 7; ATG12 autophagy related 12; CAMK2/CaMKII calcium/calmodulin-dependent protein kinase II; CNO clozapine-N-oxide; CQ chloroquine; DIA data independent acquisition; DIO double floxed inverse orf; DLG4/PSD-95 discs large MAGUK scaffold protein 4; Dox doxycycline; GABA γ-aminobutyric acid; GFP green fluorescent protein; GO gene ontology; Gi inhibitory guanine nucleotide-binding proteins; HsCHRM4/M4D human cholinergic receptor muscarinic 4; HsSYN human synapsin; KEGG Kyoto encyclopedia of genes and genomes; LAMP1 lysosomal-associated membrane protein 1; LC3-II PE conjugated microtubule-associated protein 1 light chain3; MAP1LC3/LC3 microtubule-associated protein 1 light chain 3; mPFC medial prefrontal cortex; P2A 2A self-cleaving peptide; PPI protein-protein interaction networks; PrL prelimbic cortex; RBFOX3/NeuN RNA binding protein, fox-1 homolog (C. elegans) 3; rtTA reverse tetracycline-transactivator; SDS-PAGE sodium dodecylsulfate-polyacrylamide gel electrophoresis; SHANK3 SH3 and multiple ankyrin repeat domains 3; SLC1A1/EAAC1 solute carrier family 1 (neuronal/epithelial high affinity glutamate transporter, systemXag), member 1; SNAP23 synaptosomal-associated protein 23; SNIspared nerve injury; SQSTM1/p62 sequestosome 1; SYT3 synaptotagmin 3; TRE tetracycline-responsive element; TRE3G third-generation tetracycline-responsive element.