Noradrenergic innervations of the medial prefrontal cortex mediate empathy for pain in rats via the α1 and ß receptors.

Empathy involves integrated affective and cognitive processes to share the emotional state of others. This evolutionarily conserved ability has also been identified in nonhuman primates and rodents. Our previous work demonstrated that social interaction with a cagemate rat in pain induces mechanical pain hypersensitivity in cagemate observer (CO) rats. Moreover, we also demonstrated that the medial prefrontal cortex (mPFC) and the locus coeruleus-norepinephrine (LC-NE) system are involved in this process. The LC sends noradrenergic innervations throughout the brain, and its innervation of the prefrontal cortex plays important roles in working memory and attention. The present study seeks to study the roles of the LC-to-mPFC pathway in pain empathy in rats. Selective ablation of the noradrenergic innervations of the mPFC through bilateral injections of the axonally transported catecholamine immunotoxin, saporin-conjugated antiserum to dopamine-ß-hydroxylase into the mPFC diminished mechanical pain hypersensitivity in CO rats. Bilateral intra-mPFC applications of the adrenergic α1 receptor antagonist prazosin and the ß receptor antagonist propranolol, but not the adrenergic α2 antagonist yohimbine, eliminated mechanical pain hypersensitivity in CO rats. In contrast, intra-mPFC applications of prazosin, yohimbine or propranolol did not affect the mechanical pain sensitivity of rats per se. Our results indicate that noradrenergic innervations in the mPFC mediate empathy for pain in rats via the α1 and ß receptors.

Intraoperative allogeneic transfusion is associated with postoperative delirium in older patients after total knee and hip arthroplasty.

Objective: To determine whether intraoperative transfusion of allogeneic or autologous blood is associated with an increased incidence of postoperative delirium (POD) after total knee arthroplasty (TKA) and total hip arthroplasty (THA). Methods: The medical records of 1,143 older (≥65 years old) patients who received an intraoperative blood transfusion while undergoing total knee or hip arthroplasty at the First Medical Center of Chinese PLA General Hospital from 2014 to 2019 were reviewed; of these patients, 742 (64.92%) received allogeneic blood, while 401 (35.08%) received autologous blood. Patients who received autologous transfusion were paired with those received allogeneic transfusion using 1:1 propensity score matching method. The primary outcome was POD. The secondary outcomes were postoperative complications, including heart failure, deep vein thrombosis, myocardial infarction, stroke, and lung infection. Multivariable nominal logistic regression was used to identify any independent associations between intraoperative blood transfusions and POD, and secondary postoperative complications, respectively. Results: Postoperative delirium occurred in 6.6% (49/742) of patients who had received an allogeneic blood transfusion and in 2.0% (8/401) of patients who had received an autologous blood transfusion. It is noteworthy that the multivariable logistic regression demonstrated a significant association between intraoperative allogeneic blood transfusion and POD (odds ratio [OR]: 4.11; 95% confidence interval [CI]: 1.95-9.77; p < 0.001). After PSM, Allogeneic transfusion was also the strongest predictor for POD (OR: 4.43; 95% CI: 2.09-10.58; p < 0.001). Conclusions: In the patients who had received THA or TKA, intraoperative allogeneic blood transfusions were associated with an increased risk of POD.

[Effect of propofol and operative trauma on neurodevelopment and cognitive function of developing brain in rats].

OBJECTIVE: To investigate the effect of propofol and operative trauma on the neurodevelopment and cognitive function of the developing brain and its mechanism. METHODS: A total of 104 postnatal day 13 Sprague-Dawley rats were randomly divided into 4 groups: control group (treated by 7.5 mL/kg saline and sham surgery), propofol group (treated by 75 mg/kg propofol), surgery group (with abdominal surgery under local anesthesia) and propofol+surgery group (with abdominal surgery under local anesthesia plus 75 mg/kg propofol anesthesia). Thirteen rats from each group were randomly selected for detecting the content of TNF-α in the hippocampus and the expression levels of caspase-3 and c-fos in the brain. Morris Water Maze test was used to detect the cognitive ability of the other rats at 60 days old, after which TNF-α content in the hippocampus and caspase-3 and c-fos expressions in the brain were detected. RESULTS: In 13 day-old rats, TNF-α level and caspase-3 and c-fos expressions differed significantly between the surgery group and the other 3 groups (P<0.05) and were similar among the control group, propofol group and propofol+surgery group (P>0.05). In 60-day-old rats, Morris water maze test results, TNF-α level or expressions of caspase-3 and c-fos showed no significant differences among the 4 groups. CONCLUSION: Abdominal surgery can induce inflammation in the hippocampus and neuroapoptosis in neonatal rats rather than adult rats. Single-dose propofol anesthesia does not significantly affect neurodevelopment of young rats, and can relieve central inflammatory reaction induced by surgical trauma.

Growth hormone increases lung microvascular injury in lipopolysaccharide peritonitis rats: possible involvement of NF-kappaB activation in circulating neutrophils.

AIM: To investigate the effects of growth hormone (GH) on NF-kappaB activity in neutrophils and neutrophils-mediated organ injury induced by lipopolysaccharide (LPS) in rats. METHODS: Male Wistar rats challenged with or without LPS (5 mg/kg) were treated with varied doses of GH (0.5, 1.0, and 2.0 mg/kg) for 2 or 4 h. NF-kappaB activities in circulating neutrophils were measured with electrophoretic mobility shift assays (EMSA), and I-kappaB levels in circulating neutrophils were detected by Western blot. Lung neutrophils sequestration and lung microvascular permeability were measured at 4 h after LPS challenge. RESULTS: Circulating neutrophils in LPS challenged rats had increased NF-kappaB activity and decreased I-kappaB level as compared with controls. GH dramatically increased NF-kappaB activity and I-kappaB degradation induced by LPS challenge in neutrophils. Also, subsequently, GH treatment increased lung neutrophils sequestration and lung microvascular injury induced by LPS. CONCLUSION: These results suggest that treatment of GH is harmful, instead of beneficial, to LPS-induced organ injury. Increased neutrophils' NF-kappaB activity and lung neutrophils sequestration are critical in vivo mechanisms mediating GH action on LPS-induced organ injury.

Inhibition of intracellular calcium elevation and blunting of vasopressor response due to serotonin by ginkgolide B.

The vascular effects of each individual composition in the extract of Ginkgo biloba have not been clarified. In this work, we have investigated whether ginkgolide B (GKB), a terpene lactone component from Ginkgo biloba, modulates intracellular calcium ([Ca (2+)] i) of vascular smooth muscle cells (smc) and how it influences the vasopressor response in vitro caused by serotonin (5-HT). GKB (3.2 - 9.6 microM) selectively decreased serotonin-induced [Ca (2+)] i elevations in cultured smc from bovine aorta in dose-dependent manner, while it had no effects on both resting [Ca (2+)] i and potassium-elicited [Ca (2+)] i elevations. On the other hand, GKB in a concentration of 3.2 - 9.6 microM moderately decreased the maximal pressor efficacy of serotonin by 14 - 45 % in rat mesenteric vascular beds, and the EC50 remained unchanged. The comparison study also showed GKB had no effects on noradrenaline-elicited pressor reactions. These results implicate that GKB may selectively inhibit serotonin-mediated [Ca (2+)] i mobilization in vascular smc and non-competitively alleviate the vasopressor effect of serotonin in vitro.