BACKGROUND: Central oxytocin (OT) may be a neurotransmitter or neuromodulator and play an important role in learning and memory, sexual behaviour, pain modulation and opiate tolerance and dependence. To research the interactions between oxytocinergic and opioidergic system in hippocampus has some significance.OBJECTIVE: To investigate the effects of OT administered intracerebroventricularly on evoked discharge of left dorsal hippocampal CA1 neurons in rats and the possible interactions between oxytocinergic and opioidergic system.DESIGN: A randomised controlled study.SETTING: Department of Physiology of Guangdong Medical College; Department of Physiology and Pathology of Medical College of Wuhan University.MATERIALS: The study was conducted in the Physiology Department of Medical College of Wuhan University from September 2002 to September 2003. A total of 36 male Sprague-Dawley rats were selected and randomly divided into six groups: control (NS), OT groups (0.2 mg/L, 2 mg/L and 20 mg/L), [d (CH2)5-OVT]+OT (2 mg/L), naloxone+OT (2 mg/L), with 6 rats in each group.METHODS: Single-unit recording was performed with glass microelectrode. The glass microelectrode was inserted by a micromanipulator into hippocampal CA1. The electrical activity was amplified by a microelectrode amplifier and then recorded by the biological experimental system,monitored at the same time with oscilloscope. When recording the neural discharge, electrical stimulation of the sciatic nerves was performed once 5minutes through a double stainless electrode. 5 μL oxytocin in dosage of 0.2, 2 and 20 mg/L were injected slowly into lateral ventricle via microlitre syringe. [d(CH2)5-OVT]+OT (2 mg/L) group: 2.5 μL [d(CH2)5-OVT](80 mg/L) was injected into lateral ventricle and then 2.5 μL oxytocin (2 mg/L). Naloxone+OT (2 mg/L) group: 2.5 μL naloxone (400 mg/L) was injected into lateral ventricle and then 2.5 μL oxytocin (2 mg/L). According to frequency of discharge, effect of oxytocin at various dosages on discharge induced by neurons in hippocampal CA1 area and [d (CH2)5-OVT]and naloxone on oxytocin was assayed. MAIN OUTCOME MEASURE: Changes of discharge frequency after stimulation.RESULTS: Data of totally 36 rats were entered the final analysis. ① OT (0.2 mg/L, 2 mg/L and 20 mg/L) administered by intracerebroventricularly could decrease the evoked discharge of hippocampal CA1 neurons in a dose-dependent manner. ② The inhibitory effects of OT (2 mg/L) could be blocked by pretreated intracerebroventricularly injection of [d (CH2)5-OVT](80 mg/L, 2.5 μL). ③ Intracerebroventricular injection of naloxone (400 mg/L, 2.5 μL) could attenuate the effects of OT (2 mg/L) significantly.CONCLUSION: OT can inhibit the electrical activities of hippocampal CA1 neurons to external electrical signal through activating the oxytocin receptor. Moreover, central opioid receptor is involving in the inhibitory effects of OT.

Objective:To compare the efficacy of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and posterior lumbar interbody fusion (PLIF) in the treatment of single-level lumbar disc herniation, and its influence on inflammatory factors in peripheral blood.Methods:From July 2016 to July 2018, 100 patients with single-level lumbar disc herniation admitted to the People's Hospital of Haiyan County were selected and divided into observation group ( n=50) and control group ( n=50) according to random number table method.The patients in the control group were treated with PLIF, while the patients in the observation group were treated with MIS-TLIF.The visual analogue scale (VAS), Oswestry dysfunction index (ODI) scores and the levels of inflammatory factors in peripheral blood were compared between the two groups before and after operation.The recurrence rate, incidence of complication and surgical indicators were observed. Results:The VAS and ODI scores at postoperative 1 week in the observation group were (2.32±0.85)points and (19.46±3.44)points, respectively, which were lower than those in the control group[(4.41±0.97)points and (25.78±3.63)points], the differences were statistically significant( t=13.485, 8.936, all P<0.05). The tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels in the observation group at postoperative 1 week were (2.76±0.49)ng/L and (0.78±0.13)ng/L, respectively, which were lower than those in the control group[(4.68±0.81)ng/L and (1.12±0.17)ng/L], the differences were statistically significant ( t=14.341, 11.240, all P<0.05). The operation time and bed-rest time in the observation group were (109.53±20.37)min and (30.61±3.30)d, respectively, which were shorter than those in the control group[(122.34±30.21)min and (42.87±4.68)d], and the intraoperative blood loss and postoperative drainage volume in the observation group were (181.12±40.86)mL and (60.08±11.62)mL, respectively, which were lower than those in the control group[(306.65±50.38)mL and (218.41±24.46)mL], the differences were statistically significant between the tuo groups ( t=2.486, 15.139, 13.684, 41.343, all P<0.05). The incidence of complications in the observation group was 8.00%(4/50), which was lower than 30.00%(15/50) in the control group (χ 2=19.512, P<0.05). At 3, 6 and 9 months after operation, the recurrence rates in the observation group were 0.00%, 4.00% and 8.00%, respectively, which were lower than 6.00%, 10.00% and 22.00% in the control group(χ 2=6.186, 5.674, 7.686, all P<0.05). Conclusion:Compared with PLIF, MIS-TLIF can achieve good results in the treatment of single-level lumbar disc herniation, which can relieve patients' pain, promote the recovery of waist function, reduce inflammatory response, and reduce the recurrence rate and incidence of complications.