Dataset DOI: 10.5061/dryad.76hdr7t80

Description of the data and file structure

These data were collected to investigate brain energy metabolism in mice using in vivo phosphorus magnetic resonance spectroscopy (³¹P MRS). Experiments included inter-variability, intra-variability, and awake versus anesthetized conditions. For each experiment, respiration rate and body temperature were recorded during ISIS scans, ³¹P MR spectra were acquired and processed in TopSpin, and metabolite integrals were extracted.

Note on temperature measurements: In the awake versus anesthetized experiments, temperature was measured on the abdominal surface, which underestimates core body temperature by ~3.5 °C. For mice M1 and F2, the temperature probe was slightly misplaced; however, body temperature was maintained in the same fashion as in all other experiments, and there is no reason to believe that actual body temperature deviated from 37 °C.

Full experimental and processing details are described in the Methods section of the associated publication:
Saba Molhemi, Rasmus West Knopper, Christian Stald Skoven, Thomas Beck Lindhardt, Caroline Degel, Leif Østergaard, Brian Hansen*, 2025. "Isoflurane anesthesia alters 31P magnetic resonance spectroscopy markers compared to awake mouse brain". PLOS One. DOI: *10.1371/journal.pone.0333627

Files and variables

File: Dryad.zip

Description:

This dataset contains the minimal data underlying the analyses reported in the associated manuscript.
Data are organized by experiment:

• Inter-variability
• Intra-variability
• Awake vs. Anesthetized

Each experiment folder includes three subfolders:

1. AUC

Folder: AUC/
Contains .csv files with extracted area-under-the-curve (AUC) values of ³¹P metabolites.

• File naming convention: [MouseID][Condition]and/or[Scan]_AUC.csv
  • MouseID = animal identifier (e.g., M1, F4). M = male, F = female.
  • Condition = awake or anes (for anesthetized).
    Each file corresponds to one individual mouse under one condition.
  • Scan = ISIS scan number.
• File contents:
  1. Object — name of the metabolite whose AUC was extracted; the rows appear in the following sequence: PME, Pi, PDE, PCr, γ-ATP, α-ATP, β-ATP.
  2. Integral [abs] — absolute area-under-the-curve (AUC) value for the metabolite (arbitrary units).
  3. Integral [rel] — relative AUC normalized to the phosphocreatine (PCr) signal.
  4. Peak [ppm] — chemical shift position of the metabolite peak (in parts per million, ppm).

• Rows:
  Each row in Object lists one ³¹P metabolite from the spectrum of a single mouse, with its respective Integral [abs], Integral [rel], and Peak [ppm] values in the next columns.

 2. Biometry

Folder: Biometry/
Contains .txt files recording respiration rate and body temperature during each ISIS scan.

• File naming convention: [MouseID]_[Condition]_biometry.txt
  • MouseID = animal identifier (e.g., M1, F4).
  • Condition = awake or anes or ISIS_scan_number
    Each file corresponds to the raw biometry log for one mouse in one condition.
• File contents:
  • Column headers:
    1. Time — time elapsed since the start of the recording (in seconds).
    2. Resp Rate — respiration rate at each time point (in respirations per minute).
    3. Temp 1 — body temperature (in °C).

• Rows:
  Each row represents one time point recorded during the ISIS scan, providing the instantaneous respiration rate and temperature of the mouse.

 3. Spectra

Folder: Spectra/
Contains a folder with the naming convention  [MouseID][Condition]and/or[Scan]  with one ascii-spec.txt file in each folder with the preprocessed ³¹P MR spectra exported from TopSpin.

• File contents:
  • The file has four comma-separated columns:
    1. Index – a sequential data point number (integer) used for reference.
    2. Intensity – the MRS signal amplitude in arbitrary units (a.u.), corresponding to the y-axis.
    3. Frequency – the raw spectrometer frequency value in Hz (optional for most analyses).
    4. Chemical Shift – the chemical shift in parts per million (ppm), corresponding to the x-axis.
• Rows:
  Each row corresponds to one spectral point. The spectrum is ordered from higher to lower ppm. For plotting, use the chemical shift (Column 4) as the x-axis and the intensity (Column 2) as the y-axis.