The influence of syringic acid treatment on total dopamine levels of the hippocampus and on cognitive behavioral skills.

BACKGROUND: Natural polyphenols have been investigated and are claimed to be mediators of the relationship between dopamine (DA) and memory. Therefore, we aimed to measure and evaluate the effect of syringic acid (SA) on DA expression by behavioral tests related to short-term and recognition memory in Wistar rats. METHODS: Rats were randomly assigned to control (0.5 cc corn oil, n = 10), SA (25 mg/kg/day, o.g, n = 10), Deltamethrin (DTM) (1.28 mg/kg/day o.g, n = 10) and DTM (1.28 mg/kg/day o.g, n = 10) + SA (25 mg/kg/day) groups. The Y-maze and Novel Object Recognition (NOR) tests were performed to assess cognitive and behavioral functions in the rats. Dopamine levels in the hippocampus were measured by mass spectrometry. RESULTS: Syringic acid significantly increased DA (5.45 ± 1.06 ng/ml, p = 0.0026, p < 0.05) compared with the other groups. SA increased the percent alternation (34.85 ± 0.72%, p < 0.05), time spent in the novel arm (2.88 ± 0.18 min, p < 0.05), and frequency of novel arm entries (44.91 ± 2.28%, p < 0.05), of the rats after the Y-maze test. The SA elevated the discrimination index (70.42 ± 3.59%, p < 0.001), and exploration time (30.44 ± 1.8 sec, p < 0.05) in the NOR test, and increased the short term and recognition memory in behavioral tests. CONCLUSION: Our findings support the hypothesis that SA-induced DA levels of the hippocampus may facilitate recognition and short-term memory in Wistar rats through the activation of dopaminergic receptors or pathways during the learning process, and that this can be seen in the cognitive behavior of SA-treated rats.

Protective mechanism of Syringic acid in an experimental model of Parkinson's disease.

6-Hydroxydopamine (6-OHDA) is a widely used chemical to model Parkinson's disease (PD) in rats. Syringic acid (SA) is a polyphenolic compound which has antioxidant and anti-inflammatory properties. The present study aimed to evaluate the neuroprotective role of SA in a rat model of 6-OHDA-induced PD. Parkinson's disease was created by injection of 6-OHDA into the medial forebrain bundle via stereotaxic surgery. Syringic acid was administered daily by oral gavage, before or after surgery. All groups were tested for locomotor activity, rotarod performance and catatony. Dopamine levels in SN were determined by an optimized multiple reaction monitoring method using ultra-fast liquid chromatography coupled with tandem mass spectrometry (MS/MS). The immunoreactivities for tyrosine hydroxylase (TH) and inducible nitric oxide synthase (iNOS) were detected by immunohistochemistry in frozen substantia nigra (SN) sections. Nitrite/nitrate levels, iNOS protein, total oxidant (TOS) and total antioxidant (TAS) status were assayed in SN tissue by standard kits. Motor dysfunction, impaired nigral dopamine release, increased iNOS expression and elevated nitrite/nitrate levels induced by 6-OHDA were significantly restored by SA treatment. Syringic acid significantly improved the loss of nigral TH-positive cells, while increasing TAS capacity and reducing TOS capacity in SN of PD rats. These data conclude that SA is a potential therapeutic agent for the treatment of 6-OHDA-induced rat model of PD. Syringic acid reduced the progression of PD via its neuroprotective, antioxidant and anti-inflammatory effects.

Neuroprotective Effects of Ozone Therapy After Sciatic Nerve Cut Injury.

A number of antioxidants have been used to treat peripheral nerve injury. However, there are few definitive experimental studies of ozone therapy for peripheral nerve cut injury. We aimed to examine the effects of mild level ozone therapy on sciatic nerve regeneration. One hundred adult male Wistar albino rats were randomly divided into four groups: group 1 (n=20) no cut injury or therapy; group 2 (n=20) sham; group 3 (n=30) nerve cut injury, no therapy; group 4 (n=30) nerve cut injury and ozone therapy. Sciatic functional index (SFI) and withdrawal reflex (WDR) were measured for all groups before nerve cut, at postoperative day 1, and at weeks 2, 4, 6 and 8. More myelinated (M) nerve fibers were observed after nerve cut injury in the ozone-therapy group. Significant differences were seen in plasma SOD (superoxide dismutase), CAT (catalase) and GPx (glutathione peroxidase) activities (p<0.05), and significant functional improvement was observed at postoperative weeks 2 and 4 (p<0.05) after ozone treatment. This is the first study conducted for the purpose of examining the effects of ozone therapy on sciatic nerve cut injury.

Protective effects of syringic acid on neurobehavioral deficits and hippocampal tissue damages induced by sub-chronic deltamethrin exposure.

Recent developments in the field of insecticide exposure have led to a renewed interest in alternative antioxidant therapy. The present study was to investigate the neuroprotective role of syringic acid (SA, 25 mg/kg/day) on the neurotoxicity and oxidative damage induced by deltamethrin (DTM, 1.28 mg/kg/day during two months) in CA1/3 pyramidal neurons. Animals were divided into 4 groups (n = 16/group) (250-270 g) for control, DTM, SA and DTM + SA. DTM and SA were administered by oral gavage daily. Rats that were given sub-chronic DTM had revealed a significant increase in caspase-3 levels, impaired recognition memory, reduced antioxidant activity and enhanced free radicals in the hippocampus. The results showed that SA ameliorated neurobehavioral alterations, reduced reactive oxygen/nitrogen species, pyknosis in the CA1/3 and increased antioxidant enzyme activity. In conclusion, SA (25 mg/kg/day) had potential neuroprotective and therapeutic impacts against sub-chronic DTM exposure via its antioxidant and antiapoptotic efficacy. Therefore, it can be used as a neuroprotective natural plant-derived agent against DTM-induced neurotoxicity.

Mechanism of the beneficial effect of melatonin in experimental Parkinson's disease.

This study aimed to elucidate locomotor activity changes in 6-hydroxydopamine (6-OHDA) induced Parkinson's disease (PD) and investigate the possible beneficial effects of melatonin on altered levels of locomotor activity, cyclooxygenase (COX), prostaglandin E2 (PGE2), nuclear factor kappa-B (NF-κB), nitrate/nitrite and apoptosis. Male Wistar rats were divided into five groups: vehicle (V), melatonin-treated (M), 6-OHDA-injected (6-OHDA), 6-OHDA-injected + melatonin-treated (6-OHDA-Mel) and melatonin treated + 6-OHDA-injected (Mel-6-OHDA). Melatonin was administered intraperitoneally at a dose of 10 mg/kg/day for 30 days in M and Mel-6-OHDA groups, for 7 days in 6-OHDA-Mel group. Experimental PD was created stereotactically via unilateral infusion of 6-OHDA into the medial forebrain bundle (MFB). The 6-OHDA-Mel group started receiving melatonin when experimental PD was created and treatment was continued for 7 days (post-treatment). In the Mel-6-OHDA group, experimental PD was created on the 23rd day of melatonin treatment and continued for the remaining 7 days (pre- and post-treatment). Locomotor activity performance decreased in 6-OHDA group compared with vehicle; however melatonin treatment did not improve this impairment. Nuclear factor kappa Bp65 and Bcl-2 levels were significantly decreased while COX, PGE2 and caspase-3 activity were significantly increased in 6-OHDA group. Melatonin treatment significantly decreased COX, PGE2 and caspase-3 activity, increased Bcl-2 and had no effect on NF-κB levels in experimental PD. 6-Hydroxydopamine injection caused an obvious reduction in TH positive dopaminergic neuron viability as determined by immunohistochemistry. Melatonin supplementation decreased dopaminergic neuron death in 6-OHDA-Mel and Mel-6-OHDA groups compared with 6-OHDA group. Melatonin also protected against 6-OHDA-induced apoptosis, as identified by increment in Bcl-2 levels in dopaminergic neurons. The protective effect of melatonin was more prominent for most parameter following 30 days treatment (pre- and post-) than 7 days post-treatment. In summary, melatonin treatment decreased dopaminergic neuron death in experimental PD model by increasing Bcl-2 protein level and decreasing caspase-3 activity.

Does circadian rhythm disruption induced by light-at-night has beneficial effect of melatonin on sciatic nerve injury?

Melatonin stimulates peripheral nerve regeneration. However, the precise effect of Melatonin on nerve repair in dark period have not been clarified. The aim of the present study was to investigate the effect of melatonin on sciatic nerve injury after melatonin was given to rats in the morning or evening by means of combined analysis. This is the first study to investigate the influence of melatonin on sciatic nerve in cut injury two different times of the day. 60 adult female Wistar rats were divided into 4 groups: control (Group 1), sham-operated (Group 2), sciatic nerve cut+melatonin treatment in light (Group 3), sciatic nerve cut+melatonin treatment in dark (Group 4). Melatonin was administered intraperitoneally at dose of 50 mg/kg/day for six weeks. Recovery of function was analyzed by structural (biochemical properties of the antioxidant levels and ultrastructural analysis) and functional analyses (Sciatic function index, pinch test). The data demonstrated beneficial effect of melatonin in light period. However significant beneficial effect of melatonin was detected on the recovery of the cut sciatic nerve in dark period. Melatonin treatment was unable to influence on the recovery of the cut sciatic nerve in dark period. This means that the effect of melatonin the recovery of the cut injured sciatic nerve depends on the time of treatment may be attributed to its circadian rhythm.

Comparison of the beneficial effect of melatonin on recovery after cut and crush sciatic nerve injury: a combined study using functional, electrophysiological, biochemical, and electron microscopic analyses.

PURPOSE: Following tissue injury, melatonin is known to reduce detrimental effects of free radicals by stimulating antioxidant enzymes and also to inhibit posttraumatic polymorphonuclear infiltration. Beneficial effects after peripheral nerve injury have been suggested, but not studied in detail. Therefore, we aimed to elucidate the effects of melatonin on the recovery of the lesioned rat sciatic nerve by means of combined analysis. METHODS: A total number of 90 rats were randomly distributed into six groups: control (group 1), sham-operated (group 2), sciatic nerve cut (group 3), sciatic nerve cut + melatonin treatment (group 4), sciatic nerve crush (group 5), and sciatic nerve crush + melatonin treatment (group 6). Melatonin was administered intraperitoneally at a dose of 50 mg/kg/day for 6 weeks. Recovery of function was analyzed by assessment of the sciatic functional index based on walking track analysis, somatosensory evoked potentials, biochemical quantification of malondialdehyde, antioxidant enzymes levels, and ultrastructural analysis. RESULTS: Our data showed the beneficial effect of melatonin on sciatic nerve recovery. Rats treated with melatonin demonstrated better structural preservation of the myelin sheaths compared to the nontreated group. The biochemical analysis confirmed the beneficial effects of melatonin displaying lower lipid peroxidation and higher superoxide dismutase, catalase, and glutathione peroxidase activities in sciatic nerve samples in comparison to nontreated groups. CONCLUSIONS: The beneficial effects of melatonin administration on the recovery of the cut and crush injured sciatic nerve may be attributed to its antioxidant properties. Based on these investigations, we think that our data would be helpful for clinicians who deal with peripheral nerve injuries.

Four-headed biceps brachii, three-headed coracobrachialis muscles associated with arterial and nervous anomalies in the upper limb.

A four-headed biceps brachii muscle and three-headed coracobrachialis muscle, high-originated radial artery and communication between the median and musculocutaneous nerves have been well documented in the available literature. However co-existence of these variations is rare. In this study we aimed to describe multiple variations in the upper limb and discuss their co-existence from clinical and embryological points of view.

The co-existence of the gastrocnemius tertius and accessory soleus muscles.

A bilateral gastrocnemius tertius muscle and a unilateral accessory soleus muscle were encountered during the routine educational dissection studies. The right gastrocnemius tertius muscle consisted of one belly, but the left one of two bellies. On the left side, the superficial belly of the gastrocnemius tertius muscle had its origin from an area just above the tendon of the plantaris muscle, the deep belly from the tendon of the plantaris muscle. The accessory soleus muscle originated from the posteromedial aspect of the tibia and soleal line of the tibia and inserted to the medial surface of the calcaneus. On the right side, the gastrocnemius tertius muscle had its origin from the lateral condyle of the femur, and inserted to the medial head of the gastrocnemius muscle. The co-existence of both gastrocnemius tertius and accessory soleus muscle has not, to our knowledge, been previously reported.

Anterior intermeniscal ligament: an ultrastructural study.

The aim of the present study was to investigate the detailed histological characteristics of membranous and cord-like anterior intermeniscal ligaments (AIMLs) by transmission electron microscopy (TEM) and light microscopy. Ten biopsies of AIMLs were sampled from 10 knees during total knee arthroplasty procedures. Three of them were membranous and 7 of them were cord-like. They were processed for light and TEM evaluations. Histologically, the findings in the membranous and cord-like ligaments were similar. They consisted of parallel bundles of collagen fibrils and their posterior surfaces were covered by a layer of loose well-vascularized synovial tissue. The subsynovial region consisted of loose connective tissue and was rich in blood vessels and nerve endings. Fibroblasts embedded between parallel-oriented collagen fibrils were the major cell type that we observed. Free nerve endings were squeezed between bundles of collagen fibers. Electron microscopic observations revealed the presence of Ruffini corpuscles. The presence of neural mechanoreceptors in the membranous and cord-like intermeniscal ligaments may contribute to structural and proprioceptional function of the knee. Protection of those ligaments may be valuable in planning and performing meniscal surgeries.

Anatomic evaluation and relationship between the lumbar pedicle and adjacent neural structures: an anatomic study.

OBJECTIVE: Transpedicular spinal fixation has recently been the focus of increased attention in several institutions throughout the world, but its safety and efficacy are still important questions for orthopedic surgeons. Accurate screwing through the pedicle will avoid neurologic complications and increase the stability of the instrumentation. In this study, it was aimed to analyze the anatomic relations quantitatively between the lumbar pedicle and the adjacent dural sac and nerve roots, to determine the risky areas for neural injury during transpedicular screw placement. METHODS: Ten adult cadavers were used for observation of the lumbar pedicle and its relations. After removal of the laminas and facets, the lumbar pedicles, dural sac, and nerve roots were exposed. Interpedicular distance (IPD), pedicle-inferior nerve root distance (PIRD), pedicle-superior nerve root distance (PSRD), and pedicle-dural sac distance (PDSD) were measured. RESULTS: Average distance from the lumbar pedicle to the dural sac medially and to the adjacent nerve roots superiorly and inferiorly through the cranial to caudal lumbar levels ranged from 1.29 to 1.56, from 4.12 to 5.52, and from 1.10 to 1.06 mm, respectively. The mean IPD ranged from 32.77 to 41.24 mm. There were statistically significant differences between the L5 level and other lumbar levels for IPD, PSRD, and PDSD measurements. CONCLUSIONS: These results indicate that although L5 is safer than other lumbar levels for pedicle screw insertion, an improper medial and caudal placement of a pedicular screw will carry a great risk of injury to the dural sac and inferior nerve root.

Unilateral occurrence of a chondroepitrochlearis muscle.

An abnormal muscle slip was encountered during routine dissection studies of a male cadaver. According to its origin, attachment and innervation, the abnormal slip was identified a chondroepitrochlearis muscle. Arterial and nervous supply were from the lateral thoracic artery and the medial pectoral nerve, respectively. Furthermore, no axillary arch muscle was observed. In addition, an abnormality in the attachment of the pectoralis major muscle was observed.

Multiple muscular variations in the neck region--case study.

During routine educational dissection studies, we encountered multiple muscular anomalies in a 25-year-old embalmed male cadaver. The muscular anomalies were observed on the right side. In accordance with their origin, insertion and innervation features, the abnormal muscles were considered sternocleidooccipital, sternomastoid and cleidomastoid muscles. The unilateral muscle variations were observed in both the superficial and deep layer. In the superficial layer, there were two muscles and one muscle bundle, while there was only one muscle in the deep layer. The first muscle in the superficial layer, known as sternocleidooccipital muscle, consisted of clavicular head and sternal head. The second muscle in the superficial layer was sternomastoid muscle. The muscle observed in the deep layer was cleidomastoid muscle. Additionally, a muscular bundle was observed between the sternocleidooccipital and sternomastoid muscles. A combination of these variations in the same case has not, to our knowledge, been previously described in the available literature.