Objective To investigate the difficulties of building channel in ultrasound-guided percutaneous nephrolithotomy (PCNL).Methods Surgical processes of 45 patients underwent PCNL were recorded.The difficulties and causes in building channel were analyzed.Results In the process of building channel in PCNL,60 cases of difficulties happened,41.7％ (25/60) because of depth inaccuracy of puncture and dilation,18.3％(11/60) because of angle deviation of tract dilation,15.0％(9/60) result from nondilated collecting system,13.3％(8/60) because of lacking experience in ultrasound observation.Conclusions The most often encountered difficulties is depth inaccuracy of puncture and dilation in building channel,next is angle deviation of tract dilation.To improve technique detailes is the key to gain success.

Spontaneous activity in the brain maintains an internal structured pattern that reflects the external environment, which is essential for processing information and developing perception and cognition. An essential prerequisite of spontaneous activity for perception is the ability to reverberate external information, such as by potentiation. Yet its role in the processing of potentiation in mouse superior colliculus (SC) neurons is less studied. Here, we used electrophysiological recording, optogenetics, and drug infusion methods to investigate the mechanism of potentiation in SC neurons. We found that visual experience potentiated SC neurons several minutes later in different developmental stages, and the similarity between spontaneous and visually-evoked activity increased with age. Before eye-opening, activation of retinal ganglion cells that expressed ChR2 also induced the potentiation of spontaneous activity in the mouse SC. Potentiation was dependent on stimulus number and showed feature selectivity for direction and orientation. Optogenetic activation of parvalbumin neurons in the SC attenuated the potentiation induced by visual experience. Furthermore, potentiation in SC neurons was blocked by inhibiting the glutamate transporter GLT1. These results indicated that the potentiation induced by a visual stimulus might play a key role in shaping the internal representation of the environment, and serves as a carrier for short-term memory consolidation.