title: Synchronization dynamics induced on pairs of neurons under applied weak alternating magnetic fields.
abstract: Pairs of Helix aspersa neurons show an alternating magnetic field dependent frequency synchronization (AMFS) when exposed to a weak (amplitude B0 between 0.2 and 150 Gauss (G)) alternating magnetic field (AMF) of extremely low frequency (ELF, fM = 50 Hz). We have compared the AMFS patterns of discharge with: i) the synaptic activity promoted by glutamate and acetylcholine; ii) the activity induced by caffeine; iii) the bioelectric activity induced on neurons interconnected by electric synapses. AMFS activity reveals several specific features: i) a tight coincidence in time of the pattern and frequency, f, of discharge; ii) it is induced in the time interval of field application; iii) it is dependent on the intensity of the sinusoidal applied magnetic field; iv) elicited biphasic responses (excitation followed by inhibition) run in parallel for the pair of neurons; and v) some neuron pairs either spontaneously or AMF synchronized can be desynchronized under applied higher AMF. Our electron microscopy studies reveal gap-like junctions confirming our immunocytochemistry results about expression of connexin 26 (Cx26) in 4.7% of Helix neurons. AMF and carbenoxolone did not induce any significant effect on spontaneous synchronization through electric synapses.
authors.affiliation: Laboratorio de Magnetobiología, Departamento de Anatomía e Histología, Facultad de Medicina, Universidad de Zaragoza, 50009 Zaragoza, Spain. Electronic address: mjazanza@unizar.es.
authors.forename: María J
authors.initials: MJ
authors.lastname: Azanza
authors.forename: A
authors.initials: A
authors.lastname: del Moral
authors.forename: A C
authors.initials: AC
authors.lastname: Calvo
authors.forename: R N
authors.initials: RN
authors.lastname: Pérez-Bruzón
authors.forename: C
authors.initials: C
authors.lastname: Junquera
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000072259:Connexin 26; D017630:Connexins / Q000096:biosynthesis; D054351:Electrical Synapses / Q000187:drug effects / Q000502:physiology; D018698:Glutamic Acid / Q000494:pharmacology; D006372:Helix, Snails / Q000502:physiology*; D060526:Magnetic Fields; D008854:Microscopy, Electron; D009474:Neurons / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D017630:Connexins; D000072259:Connexin 26; D018698:Glutamic Acid; D000109:Acetylcholine
keywords: AMF; AMF sinusoidal frequency; AMFS; Ach; Bioelectromagnetism; CBX; Cx26; ELF; ELF-magnetic field effects; EMF; G; Glut; Inx; MF; Magnetobiology; Mollusc brain ganglia; N-methyl-d-aspartate; NMDA; Neuromagnetism; Pnx; RF; RN; Ringer solution; SAR; SD-CE; SMF; Synchronization of neuron activity; T; TEA; TEM; W; acetylcholine; alternating magnetic field; bioelectric frequency (spikes/s≡s/s); caffeine; carbenoxolone; cf; connexin 26; e; electromagnetic field; electron charge; extremely low frequency; f; f(M); gauss; glutamate; innexins; magnetic field; magnetic field dependent frequency synchronization; membrane bilayer superdiamagnetism and Ca(2+)-coulomb explosion; pannexin; radiofrequency; specific absorption rate; static magnetic field; tesla; tetraethylammonium; transmission electron microscopy; washing neuron bath with fresh Ringer solution