Sensitivity of spinal neurons to GABA and glycine during voluntary movement in behaving monkeys.

GABAergic and glycinergic inhibition play key roles in the function of spinal motor pathways. However, there is little direct information on the extent to which inhibition controls the activity of spinal neurons during behavior or the relative effectiveness of GABA and glycine on cell activity under normal conditions. These issues were investigated in three macaque monkeys trained to perform voluntary ramp-and-hold wrist movements and grip. Pipettes with an extracellular recording electrode and iontophoresis barrels were used to eject GABA, glycine, and/or their respective antagonists, bicuculline and strychnine, as the activity of single neurons was recorded in the C6-T1 spinal segments during hand movements. The firing rate of the vast majority of neurons decreased when an inhibitory neurotransmitter was ejected from the electrode, suggesting that most movement-related spinal neurons are sensitive to both GABA and glycine. Most movement-related neurons exhibited increased activity during iontophoresis of an antagonist, suggesting that both GABAergic and glycinergic inhibition actively regulate the majority of spinal neurons during movement. These conclusions were supported by the responses of neurons tested with both agonists or both antagonists. Bicuculline and strychnine produced the largest increases in firing rate during dynamic movements (ramp phase), smaller increases during maintained torque/force (hold phase), and the smallest increase during the rest period. Since excitatory inputs also tend to increase progressively from rest to static to dynamic muscle contractions, this result is consistent with coupled excitatory and inhibitory inputs to spinal neurons during movement.

The outcomes of scleral buckling versus re-vitrectomy for the treatment of recurrent inferior retinal detachment in silicone oil tamponade eyes.

PURPOSE: In this retrospective study we evaluated the anatomic outcomes of scleral buckling (SB) versus re-vitrectomy for the treatment of recurrent inferior retinal detachment (RD) in silicone oil (SiO) tamponade eyes after primary vitrectomy. METHODS: There were 103 patients (103 eyes) enrolled in this study. All patients had recurrent inferior RD in the SiO-filled eyes within 6 months after the primary vitrectomy, and were treated by either SB or re-vitrectomy. Patients were divided into two groups based on different surgical procedures: the SB group (49 eyes) and the re-vitrectomy group (54 eyes). Anatomic reattachment of the retina was measured after reoperation. Based on different retinal proliferation states in different postoperative periods after primary vitrectomy, we also compared the anatomic outcomes of the two surgical procedures in two specific postoperative periods, early period (≤1 month) and late period (1-6 months). RESULTS: The SB and re-vitrectomy groups exhibited similar retinal reattachment rate (65.3% versus 72.2%, p = 0.449) after reoperation. In the re-vitrectomy group, the retinal reattachment rate was similar in the early period and the late period (70.8% versus 73.3%, p = 0.839). However, the retinal reattachment rate was significantly higher in the early period than that of the late period (80.8% versus 47.8%, p = 0.016) in the SB group. In the early surgery groups, the retinal reattachment rate was similar in the SB group compared to the re-vitrectomy group (80.8% versus 70.8%, p = 0.411). While in the late surgery groups, retinal reattachment rate was trended higher in the re-vitrectomy group compared to the SB group (73.3% versus 47.8%, p = 0.058). CONCLUSION: For recurrent inferior RD in SO-filled eyes, SB surgery provides similar therapeutic effectiveness with satisfactory anatomic outcomes compared to the re-vitrectomy. For eyes with recurrent inferior RD in the early period (≤1 month) after primary vitrectomy, SB surgery may be a better choice since it causes less complication; while in the late period (1-6 months) after primary vitrectomy, re-vitrectomy may be recommended, especially for the eyes with severe anterior proliferative vitreoretinopathy and retinal foreshortening.

[Roles of entopeduncular nucleus in acupuncture analgesia and caudate-putamen nucleus stimulation-induced analgesia].

The present study was to investigate whether entopeduncular nucleus (EP) is involved in caudate-putamen nucleus (CPu) stimulation-induced analgesia and in acupuncture analgesia. It was found that the foot-withdrawal latency elicited by radiant heat exposure was increased after electroacupuncture analgesia (EA), and the nociceptive responses of neurons in parafascicular nucleus (Pf) were inhibited after EA or after excitation of CPu neurons in normal rats, but the foot-withdrawal latency and nociceptive responses of Pf neurons were unchanged by EA or excitation of CPu in the rats with lesion of EP by local application of kainic acid. The results obtained with microinjeciton of saline instead of kainic acid into the EP were the same with those in the nonlesioned control group. The differences in the results between the lesion group and the other groups were significant ( <0.05). It is suggested that EP is involved in acupuncture analgesia and also plays an important role in caudate-putamen nucleus stimulation-induced analgesia.