{"doi":"10.1038/s41598-021-95646-8","title":"UHPLC–electrospray ionization–mass spectrometric analysis of brain cell-specific glucogenic and neurotransmitter amino acid content","abstract":"Abstract Astrocyte glycogen, the primary energy reserve in brain, undergoes continuous remodeling by glucose passage through the glycogen shunt prior to conversion to the oxidizable energy fuel l -lactate. Glucogenic amino acids (GAAs) are a potential non-glucose energy source during neuro-metabolic instability. Current research investigated whether diminished glycogen metabolism affects GAA homeostasis in astrocyte and/or nerve cell compartments. The glycogen phosphorylase (GP) inhibitor 1,4-dideoxy-1,4-imino- d -arabinitol (DAB) was injected into the ventromedial hypothalamic nucleus (VMN), a key metabolic-sensing structure, before vehicle or l -lactate infusion. Pure VMN astrocyte and metabolic-sensory neuron samples were obtained by combinatory immunocytochemistry/laser–catapult-microdissection for UHPLC–electrospray ionization–mass spectrometry (LC–ESI–MS) GAA analysis. DAB inhibition of VMN astrocyte aspartate and glutamine (Gln) levels was prevented or exacerbated, respectively, by lactate. VMN gluco-stimulatory nitric oxide (NO; neuronal nitric oxide synthase-immunoreactive (ir)-positive) and gluco-inhibitory γ-aminobutyric acid (GABA; glutamate decarboxylase 65/67 -ir-positive) neurons exhibited lactate-reversible asparate and glutamate augmentation by DAB, but dissimilar Gln responses to DAB. GP inhibition elevated NO and GABA nerve cell GABA content, but diminished astrocyte GABA; these responses were averted by lactate in neuron, but not astrocyte samples. Outcomes provide proof-of-principle of requisite LC–ESI–MS sensitivity for GAA measurement in specific brain cell populations. Results document divergent effects of decreased VMN glycogen breakdown on astrocyte versus neuron GAAs excepting Gln. Lactate-reversible DAB up-regulation of metabolic-sensory neuron GABA signaling may reflect compensatory nerve cell energy stabilization upon decline in astrocyte-derived metabolic fuel.","journal":"Scientific Reports","year":2021,"id":184510,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":11,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9552,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":740420,"name":"Prabhat R. Napit","orcid":null,"position":1,"is_corresponding":false},{"id":331580,"name":"Mostafa M.H. Ibrahim","orcid":"0000-0003-2038-9933","position":2,"is_corresponding":false},{"id":331582,"name":"Karen P. Briski","orcid":"0000-0002-7648-1395","position":3,"is_corresponding":false},{"id":332976,"name":"Khaggeswar Bheemanapally","orcid":null,"position":0,"is_corresponding":true}],"reference_count":42,"raw_metadata":null,"created_at":"2026-07-18T23:48:30.970730Z","pmid":"34373537","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}