SeyyedJavad Mirnajafizadeh; Yaghob Fattollahi; Amir Shojaee; Azam Asgari; Fatemeh Rostami
Volume 21, Issue 5 , September and October 2014, , Pages 951-959
Abstract
Background and purpose: Nowadays repeated transcranial magnetic stimulation (rTMS) is being used as a treatment for some neurological disorders, but its effect on neuronal activity and synaptic plasticity has not been completely determined. The purpose of this study was to evaluate the effect of chronic ...
Read More
Background and purpose: Nowadays repeated transcranial magnetic stimulation (rTMS) is being used as a treatment for some neurological disorders, but its effect on neuronal activity and synaptic plasticity has not been completely determined. The purpose of this study was to evaluate the effect of chronic rTMS on the ability of synaptic plasticity.
Materials and Methods: rTMS was applied to the hippocampal region for 14 days. One week following termination of rTMS, the amount of synaptic long-term potentiation (LTP) in animals was investigated and compared with control group. High-frequency stimulation (HFS) was applied to the perforant path for LTP induction, andfield potentials were recorded from granular layer of the dentate gyrus. Baseline field potential was recorded 10 minutes before HFS. An increase of at least 20% in population spike amplitude was measured as an index of synaptic potentiation.To compare the effects of rTMS on measured parameters, we used t-test and two way ANOVA followed by Benferroni test (Prism 8 software).
Results: Obtained data showed that, following 14 days of rTMS application causeda reduction in population spike amplitude compared to the control group (P
Javad Mirnajafi-zade; Ali Gorji; Yaghoob Fathollahi; Mahyar Janahmadi; Parviz shahabi; Hadi Kazemi
Volume 18, Issue 3 , September and October 2011, , Pages 148-157
Abstract
Background and Purpose: Spreading depression (SD) is a neuronal-glyal depolarization، with a possible role in different neurological disorders including epilepsy and migraine aura. Initiation and propagation of SD modulate excitability of neuronal network. The aim of the present study was to investigate ...
Read More
Background and Purpose: Spreading depression (SD) is a neuronal-glyal depolarization، with a possible role in different neurological disorders including epilepsy and migraine aura. Initiation and propagation of SD modulate excitability of neuronal network. The aim of the present study was to investigate electrophysiological characteristics of neurons of the lateral amygdala in the late phase of excitability during SD. Methods and Materials: In this experimental study، 6 male rats were used. We used horizontal amygdala-hippocampus-neocortex slice in which SD was induced by KCl application in each brain structure. After superfusion of these slices with GABAA receptor antagonist bicuculline (1.25 µmol/L) for 45 min، initiation of SD evoked ictal epileptic activity in all tested slices. The induction of SD in the lateral amygdala resulted in presence of interictal and ictal epileptiform field potentials and intracellular paroxysmal shift (PDS). For data analysis، paired t-test and one-way ANOVA were used in Sigma Stat 3 software. Results: The results demonstrated that SD moved the resting membrane potential (before -60.3±0.5 and after -52.8±0.78) towards depolarization after inducing the spreading depression in lateral Amygdale (P