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Title: EFFECTS OF OSMOLARITY ON ULTRASOUND-INDUCED MEMBRANE DEPOLARIZATION IN ISOLATED CRAYFISH MOTOR AXON
Abstract—We have previously identified a novel non-selective membrane conductance (gUS) opened by focused ultrasound (FUS) in crayfish motor axons. In the work described here, we studied gUS properties further by comparing FUS-evoked depolarization (FUSD) in control and hypotonic saline with 75% of control osmolarity. The FUS was a train of 20 FUS bursts (2.1 MHz and 50 ms per burst) delivered at 1 kHz. The amplitude, onset latency, frequency of occurrence and duration of FUSD were compared in a 15-min time window before and after switching to hypotonic saline. Significant increases were observed for amplitude (p < 0.001) and frequency of occurrence (p < 0.01) while the onset latency exhibited a significant decrease (p < 0.001). FUSD duration did not significantly differ. These results support predictions based on our hypothesis that gUS is mediated by opening of nanopores in the lipid bilayer and that stretching of axonal membrane caused by swelling at low osmolarity should increase the probability of nanopore formation under FUS. The FUSD parameters, in addition, exhibited time-dependent trends when the window of observation was expanded to 45 min in each saline. The statistical significance of amplitude and duration differed between 15- and 45-min time windows, indicating the presence of adaptive responses of axonal membrane to osmotic manipulation. (E-mail: jenweilin@bu.edu) © 2022 Published by Elsevier Inc. on behalf of World Federation for Ultrasound in Medicine & Biology.  more » « less
Award ID(s):
1707865
PAR ID:
10475332
Author(s) / Creator(s):
Publisher / Repository:
Elsevier
Date Published:
Journal Name:
Ultrasound in medicine biology
ISSN:
0301-5629
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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