Are presynaptic actions of general anesthetics responsible for frequency-dependent modification of synaptic transmission in the rat hippocampal CA1?
IV anesthetics, but not volatile drugs, enhance the discharge of a readily releasable pool of GABA vesicles from presynaptic terminals. Depletion of an active pool of GABA after high-frequency stimuli would produce frequency- and use-dependent recurrent inhibition in the presence of IV anesthetics. The stimulus frequency-dependent modification of synaptic transmission might be responsible for the unsuccessful immobilization or hypnosis during general anesthesia after IV anesthetic administration.
For PTVs including prostate, seminal vesicles, and lymph nodes, IMRT performed better in dose sparing for bladder, rectum, and small bowel than did RapidArc. For PTVs including prostate and seminal vesicles, RapidArc with two arcs provided plans comparable to those for IMRT. The treatment delivery is more efficient with RapidArc.