A surgical technique for implantation of the vibrant soundbridge middle ear implant in dogs.

Objective: To report a surgical implantation of the Vibrant Soundbridge (VSB) middle ear implant in dogs.

Study Design: Pilot study.

Animals: Dogs (n=3).

Tibial nerve somatosensory evoked potentials in dogs with degenerative lumbosacral stenosis.

Objective: To determine somatosensory evoked potentials (SEPs) in dogs with degenerative lumbosacral stenosis (DLS) and in healthy dogs.

Study Design: Clinical and experimental study.

Animals: Dogs with DLS (n = 21) and 11 clinically normal dogs, age, and weight matched.

Differences between somatosensory-evoked potentials recorded from the ventral posterolateral thalamic nucleus, primary somatosensory cortex and vertex in the rat.

Somatosensory-evoked potential (SEP) components recorded over the primary somatosensory cortex (SI) and vertex in the rat within the 10-30 ms latency range were characterised with respect to the anatomy and function of the primary somatosensory pathway. To this aim, these components were compared to SEP components in the similar latency range recorded from the ventral posterolateral thalamic (VPL) nucleus, a nucleus known to be part of the subcortical structure of the primary somatosensory pathway and were described with respect to their stimulus-response characteristics and their response to the mu-opioid agonist fentanyl. The VPL positive (P)11-negative (N)18-P22 and SI P13-N18-P22 differed with respect to peak occurrence (P11 versus P13, respectively) and waveform morphology, but did not differ with respect to stimulus-response characteristics and their response to fentanyl.

Differences between primary somatosensory cortex- and vertex-derived somatosensory-evoked potentials in the rat.

The somatosensory-evoked potential (SEP) elicited by high-intensity stimulation potentially provides a reliable indicator of analgesic efficacy since it reflects the level of activation of the nociceptive system. In the present study, components in the 10-30-ms latency range of SEPs recorded over the primary somatosensory cortex (SI-SEPs) and vertex (Vx-SEP) in the rat were characterized and compared. SEPs were elicited by electrical tail-base stimulation, and SI-SEPs and Vx-SEPs were recorded simultaneously.

Evaluation of methods for eliciting somatosensory-evoked potentials in the awake, freely moving rat.

To standardise the method of eliciting somatosensory-evoked potentials (SEPs), SEPs were generated by electrical stimulation of different stimulus sites and recorded bilaterally from the primary somatosensory cortex (S1) and from midline in awake, freely moving rats. Increasing stimulus intensity enhanced amplitudes of all SEPs. At supramaximal stimulation, SEPs following vibrissae and tail stimulation (V-SEP and Ta-SEP, respectively) but not following trunk stimulation (Tr-SEP), fulfilled our criterion of signal-to-noise ratio >or=4.