Cranial manipulation affects cholinergic pathway gene expression in aged rats

Context Age-dependent dementia is a devastating disorder afflicting a growing older population. Although pharmacological agents improve symptoms of dementia, age-related comorbidities combined with adverse effects often outweigh their clinical benefits. Therefore, nonpharmacological therapies are being investigated as an alternative. In a previous pilot study, aged rats demonstrated improved spatial memory after osteopathic cranial manipulative medicine (OCMM) treatment. Objectives In this continuation of the pilot study, we examine the effect of OCMM on gene expression to elicit possible explanations for the improvement in spatial memory. Methods OCMM was performed on six of 12 elderly rats every day for 7 days. Rats were then euthanized to obtain the brain tissue, from which RNA samples were extracted. RNA from three treated and three controls were of sufficient quality for sequencing. These samples were sequenced utilizing next-generation sequencing from Illumina NextSeq. The Cufflinks software suite was utilized to assemble transcriptomes and quantify the RNA expression level for each sample. Results Transcriptome analysis revealed that OCMM significantly affected the expression of 36 genes in the neuronal pathway (false discovery rate [FDR] <0.004). The top five neuronal genes with the largest-fold change were part of the cholinergic neurotransmission mechanism, which is known to affect cognitive function. In addition, 39.9% of 426 significant differentially expressed (SDE) genes (FDR<0.004) have been previously implicated in neurological disorders. Overall, changes in SDE genes combined with their role in central nervous system signaling pathways suggest a connection to previously reported OCMM-induced behavioral and biochemical changes in aged rats. Conclusions Results from this pilot study provide sufficient evidence to support a more extensive study with a larger sample size. Further investigation in this direction will provide a better understanding of the molecular mechanisms of OCMM and its potential in clinical applications. With clinical validation, OCMM could represent a much-needed low-risk adjunct treatment for age-related dementia including Alzheimer’s disease.

Pinocembrin relieves hip fracture-induced pain by repressing spinal substance P signaling in aged rats

Whether pinocembrin (PCN) could be utilized to alleviate hip fracture-induced pain is investigated in this research. Aged rats with hip fractures were treated with vehicle or 80 mg/kg/day PCN from week 3 to week 4. Then hind paw mechanical allodynia, unweighting, warmth, and thickness were measured. The microglia and astrocytes activation and proliferation markers in the spinal dorsal horn were detected with real-time PCR and immunofluorescence staining. The relative expression of substance P and its receptor, tachykinin receptor 1 (Tacr1), were detected with enzyme-linked immunosorbent assay (ELISA) and Western blots. The antinociceptive effect of Tacr1 inhibitor LY303870 was also testified. PCN alleviated hip fracture-induced hind paw nociceptive (allodynia and unweighting) and vascular changes (warmth and thickness) in aged rats with diminished microglia and astrocytes activation and proliferation in the spinal dorsal horn. Up-regulated substance P and Tacr1 were induced after hip fracture, which could be reversed by PCN treatment. Furthermore, LY303870 treatment partially reversed both spinal nociceptive sensitization and vascular changes after hip fracture. Substance P signaling contributes to the nociceptive and vascular changes observed in the hip fracture, which could be alleviated by PCN.

Effects of Chlorogenic Acid on Epileptic Behavior and mRNA Expressions of Brain Derived Neurotrophic Factor in the Brain of Aged Rats

Introduction: The present study was conducted to evaluate the effect of chlorogenic acid (CA) and Diazepam (DZP) on epileptic complication that induced by repetitive intra-peritoneal injections of pentylenetetrazle (PTZ) in aged rats. Methods: Twenty-four month-old male Wistar rats (age > 12 months, 300-350 g) were divided in 4 experimental groups. Animal in control group (PTZ + Vehicle) received only PTZ. Animal in treated groups (PTZ + DZP, PTZ + CA10 and PTZ + 25) received diazepam 2 mg/kg, CA 10 mg/kg, or CA 25 mg/kg. All drugs injection were performed 30 min prior to each PTZ injection. Epilepsy was induced by injection of subconvulsive dose of PTZ every other day until the rats were completely kindled or epileptic. After each PTZ injection, animal was monitored for 40 min and epileptic behaviors were scored. At the end of the study, rats were sacrificed and the brains removed for evaluation of histological changes and Brain Derived Neurothrophic Factor (BDNF) gene expression. Results: CA at dose of 25 mg/kg reduced percent of generalized tonic-clonic seizure (GTCS) in aged rats (24%) in compared to control group (50%) (p < 0.05). The latencies to the start of GTCS were decreased in both dose of CA (p < 0.05). Also, the percent of survived neurons in rats treated with CA (154%) were significantly higher relative to that of control animals (100%) (p < 0.05). The mRNA levels of BDNF significantly increased in CA treated rats (p < 0.05). Conclusion: Hence, these findings revealed that CA have antiepileptic, neuroprotective and trophic effects in aged rats. CA can protect aged brain from deteriorative processes and save neurons during epilepsy in rats.