Epilepsy is a severe neurological and mental disorder, and not all patients adequately respond to the current treatments. Dynamin 1 plays a key role in synaptic endocytosis and the modulation of neurological function.
Cultured hippocampal neurons were used in the study. First, the viability of neurons was determined by the CCK-8 assay after culturing in magnesium-free medium, DMSO, dynasore (dynamin agonist), and PIP2 (dynamin antagonist). Then, the effect of dynasore on seizure activity was evaluated. Next, we tested the levels of phospho-dynamin 1/total dynamin 1 and dynamin 1 mRNA in the control group and four epilepsy groups. Moreover, the uptake of tetramethylrhodamine-dextran in the different groups was measured.
Dephospho-dynamin 1 expression was significantly increased in hyperexcitable neurons, while there was no change in total dynamin 1 level. The level of dephospho-dynamin 1 in hyperexcitable neurons was reduced when cultured with dynasore but increased with PIP2 treatment. Activity-dependent bulk endocytosis (ADBE) was upregulated in hyperexcitable neurons. Along with a decrease in dephospho-dynamin 1 level, ADBE was also downregulated with dynasore treatment, while PIP2 did not affect ABDE. The close link between the dephosphorylation status of dynamin 1 and ADBE suggests that ADBE activation depends on dynamin 1 dephosphorylation.
Dephospho-dynamin 1 triggers ADBE to meet the requirements of high-frequency discharges during epileptic seizures.

Tauopathies are a class of neurodegenerative diseases that are characterized by pathological aggregation of tau protein, which is accompanied by synaptic disorders. However, the role of tau in endocytosis, a fundamental process in synaptic transmission, remains elusive. Here, we report that forced expression of human tau (hTau) in mouse cortical neurons impairs endocytosis by decreasing the level of the GTPase dynamin 1 via disruption of the miR-132-MeCP2 pathway; this process can also be detected in the brains of Alzheimer\'s patients and hTau mice. Our results provide evidence for a novel role of tau in the regulation of presynaptic function.

Dynamin 1 is a neuron-specific guanosine triphosphatase (GTPase) that is an essential component of membrane fission during synaptic vesicle recycling and endocytosis. This study evaluated the dynamin 1 expression pattern in the acute lithium-pilocarpine rat model and in patients with temporal lobe epilepsy (TLE) and investigated whether altering the dynamin 1 expression pattern affects epileptic seizures in vivo and in vitro. The immunofluorescence, western blot analysis, and reverse transcription-PCR results show that the dynamin 1 expression level increased significantly in experimental rats from day 1 to day 7 after the onset of seizures and was significantly higher in TLE patients. The behavioral study revealed that inhibiting dynamin 1 increased the latency time of the first seizure and decreased the frequency and severity of the seizures. In addition, electrophysiological recordings from brain slices showed that inhibiting dynamin 1 reduces the frequency of Mg-free induced seizure-like activity. The anticonvulsant effect of dynasore was more effective at 10 µM than at 1 µM or 160 µM. These results indicate that the altered level of dynamin 1 may contribute to the development of epileptic seizures and that the targeted regulation of dynamin 1 activity may control epileptic seizures.