The ability of carbon nanoparticles to increase transmembrane current of cations coincides with impaired synaptic neurotransmission

Biochim Biophys Acta Biomembr. 2022 Feb 1;1864(1):183817. doi: 10.1016/j.bbamem.2021.183817. Epub 2021 Nov 9.


Here, carbon nanodots synthesized from β-alanine (Ala-CDs) and detonation nanodiamonds (NDs) were assessed using (1) radiolabeled excitatory neurotransmitters L-[14C]glutamate, D-[2,33H]aspartate, and inhibitory ones [3H]GABA, [3H]glycine for registration of their extracellular concentrations in rat cortex nerve terminals; (2) the fluorescent ratiometric probe NR12S and pH-sensitive probe acridine orange for registration of the membrane lipid order and synaptic vesicle acidification, respectively; (3) suspended bilayer lipid membrane (BLM) to monitor changes in transmembrane current. In nerve terminals, Ala-CDs and NDs increased the extracellular concentrations of neurotransmitters and decreased acidification of synaptic vesicles, whereas have not changed sufficiently the lipid order of membrane. Both nanoparticles, Ala-CDs and NDs, were capable of increasing the conductance of the BLM by inducing stable potential-dependent cation-selective pores. Introduction of divalent cations, Zn2+ or Cd2+ on the particles` application side (cis-side) increased the rate of Ala-CDs pore-formation in the BLM. The application of positive potential (+100 mV) to the cis-chamber with Ala-CDs or NDs also activated the insertion as compared with the negative potential (-100 mV). The Ala-CD pores exhibited a wide-range distribution of conductances between 10 and 60 pS and consecutive increase in conductance of each major peak by ~10 pS, which suggest the clustering of the same basic ion-conductive structure. NDs also formed ion-conductive pores ranging from 6 pS to 60 pS with the major peak of conductance at ~12 pS in cholesterol-containing membrane. Observed Ala-CDs and NDs-induced increase in transmembrane current coincides with disturbance of excitatory and inhibitory neurotransmitter transport in nerve terminals.

Keywords: Carbon nanodots; Detonation nanodiamonds; Ion-selective pores; Planar lipid bilayers; Synaptic neurotransmission.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alanine / chemical synthesis
  • Alanine / chemistry
  • Animals
  • Aspartic Acid / chemical synthesis
  • Aspartic Acid / chemistry
  • Aspartic Acid / pharmacology
  • Carbon / chemistry
  • Carbon / pharmacology
  • Carbon Radioisotopes / chemistry
  • Carbon Radioisotopes / pharmacology
  • Cations / pharmacology
  • Cerebral Cortex / metabolism*
  • Cerebral Cortex / radiation effects
  • Cholesterol / chemistry
  • Glutamic Acid / chemical synthesis
  • Glutamic Acid / chemistry
  • Glutamic Acid / pharmacology
  • Lipid Bilayers / chemistry
  • Nanodiamonds / chemistry
  • Nanoparticles / chemistry*
  • Neurotransmitter Agents / chemistry
  • Neurotransmitter Agents / pharmacology
  • Rats
  • Synapses / chemistry
  • Synapses / drug effects*
  • Synaptic Transmission / drug effects*
  • Synaptic Transmission / physiology
  • Synaptic Vesicles / chemistry*
  • Synaptic Vesicles / drug effects
  • Synaptic Vesicles / metabolism
  • gamma-Aminobutyric Acid / chemical synthesis
  • gamma-Aminobutyric Acid / chemistry
  • gamma-Aminobutyric Acid / pharmacology


  • Carbon Radioisotopes
  • Cations
  • Lipid Bilayers
  • Nanodiamonds
  • Neurotransmitter Agents
  • Aspartic Acid
  • Glutamic Acid
  • gamma-Aminobutyric Acid
  • Carbon
  • Cholesterol
  • Alanine