The Effects of Diagnostic Ultrasound Waves on Excitability Threshold and Cellular Apoptosis Induced by Pentylenetetrazole in Hippocampal Neurons

Abstract

Objective: Ultrasound (US) is a medical imaging technique with various therapeutic and diagnostic applications. This study aimed to investigate the effects of diagnostic US waves with a frequency of 3.5 MHz and intensity of 65 mW/cm2 on the threshold of neurons' excitability and the apoptosis induced by pentylenetetrazole (PTZ) in rats. Materials and Methods: Forty-seven-day-old Wistar rats were randomly divided into five groups. The first group was assigned as the control group, the second group was seized by intraperitoneal injection of PTZ, the third, fourth, and fifth groups were given US waves for 5, 10, and 15 minutes, respectively, followed by intraperitoneal PTZ injection. The animals were observed and their behavior, including the seizure duration, the number of seizures, and the seizure cessation time were recorded for 30 minutes. Subsequently, animals' hippocampi were removed in order to measure B-cell lymphoma protein 2 (BCL-2) and BCL-2-associated X (BAX) by using Western blotting techniques. Results: The results showed that US waves in the diagnostic frequency range with a duration of 5, 10, and 15 minutes significantly increased the seizure duration in the target groups. Furthermore, the simultaneous use of US with the desired times with PTZ increased the number of seizures and prolonged the seizure cessation time. PTZ increased the BAX/BCL-2 proteins ratio, and the concomitant use of US and PTZ intensified the impairment. Conclusion: This study showed that exposure to US increased the excitability of neurons and exacerbated the seizure effects of PTZ as well as PTZ-induced apoptosis in the rat hippocampal cells.

Keywords

• ultrasound waves
• seizures
• apoptosis
• hippocampus
• pentylenetetrazole