Apparent absence of hypothalamic cholinergic neurons in the common ostrich and emu: Implications for global brain states during sleep.

We examined the presence/absence and parcellation of cholinergic neurons in the hypothalami of five birds: a Congo grey parrot (Psittacus erithacus), a Timneh grey parrot (P. timneh), a pied crow (Corvus albus), a common ostrich (Struthio camelus), and an emu (Dromaius novaehollandiae). Using immunohistochemistry to an antibody raised against the enzyme choline acetyltransferase, hypothalamic cholinergic neurons were observed in six distinct clusters in the medial, lateral, and ventral hypothalamus in the parrots and crow, similar to prior observations made in the pigeon. The expression of cholinergic nuclei was most prominent in the Congo grey parrot, both in the medial and lateral hypothalamus. In contrast, no evidence of cholinergic neurons in the hypothalami of either the ostrich or emu was found. It is known that the expression of sleep states in the ostrich is unusual and resembles that observed in the monotremes that also lack hypothalamic cholinergic neurons. It has been proposed that the cholinergic system acts globally to produce and maintain brain states, such as those of arousal and rapid-eye-movement sleep. The hiatus in the cholinergic system of the ostrich, due to the lack of hypothalamic cholinergic neurons, may explain, in part, the unusual expression of sleep states in this species. These comparative anatomical and sleep studies provide supportive evidence for global cholinergic actions and may provide an important framework for our understanding of one broad function of the cholinergic system and possible dysfunctions associated with global cholinergic neural activity.

Putative adult neurogenesis in palaeognathous birds: The common ostrich (Struthio camelus) and emu (Dromaius novaehollandiae).

In the current study, we examined adult neurogenesis throughout the brain of the common ostrich (Struthio camelus) and emu (Dromaius novaehollandiae) using immunohistochemistry for the endogenous markers PCNA which labels proliferating cells, and DCX, which stains immature and migrating neurons. The distribution of PCNA and DCX labelled cells was widespread throughout the brain of both species. The highest density of cells immunoreactive to both markers was observed in the olfactory bulbs and the telencephalon, especially the subventricular zone of the lateral ventricle. Proliferative hot spots, identified with strong PCNA and DCX immunolabelling, were identified in the dorsal and ventral poles of the rostral aspects of the lateral ventricles. The density of PCNA immunoreactive cells was less in the telencephalon of the emu compared to the common ostrich. Substantial numbers of PCNA immunoreactive cells were observed in the diencephalon and brainstem, but DCX immunoreactivity was weaker in these regions, preferentially staining axons and dendrites over cell bodies, except in the medial regions of the hypothalamus where distinct DCX immunoreactive cells and fibres were observed. PCNA and DCX immunoreactive cells were readily observed in moderate density in the cortical layers of the cerebellum of both species. The distribution of putative proliferating cells and immature neurons in the brain of the common ostrich and the emu is widespread, far more so than in mammals, and compares with the neognathous birds, and suggests that brain plasticity and neuronal turnover is an important aspect of cognitive brain functions in these birds.

Extinction of eastern Sahul megafauna coincides with sustained environmental deterioration.

Explanations for the Upper Pleistocene extinction of megafauna from Sahul (Australia and New Guinea) remain unresolved. Extinction hypotheses have advanced climate or human-driven scenarios, in spite of over three quarters of Sahul lacking reliable biogeographic or chronologic data. Here we present new megafauna from north-eastern Australia that suffered extinction sometime after 40,100 (±1700) years ago. Megafauna fossils preserved alongside leaves, seeds, pollen and insects, indicate a sclerophyllous forest with heathy understorey that was home to aquatic and terrestrial carnivorous reptiles and megaherbivores, including the world's largest kangaroo. Megafauna species diversity is greater compared to southern sites of similar age, which is contrary to expectations if extinctions followed proposed migration routes for people across Sahul. Our results do not support rapid or synchronous human-mediated continental-wide extinction, or the proposed timing of peak extinction events. Instead, megafauna extinctions coincide with regionally staggered spatio-temporal deterioration in hydroclimate coupled with sustained environmental change.

Review on emu products for use as complementary and alternative medicine.

Emu (Dromaius novaehallandiae), the flightless bird native to Australia and found in many countries, is receiving much attention for its nutritional benefits as well as its medicinal value. Emu oil contains high amounts of polyunsaturated fatty acids and antioxidants. It has potent anti-inflammatory actions and thus can be used topically and orally to treat conditions such as mucositis, inflammatory bowel syndrome, and auricular inflammation, and to prevent chemotherapy-induced bone loss. Emu oil also has a hypocholesterolemic effect, transdermal penetration-enhancing activity, cosmetic and insect repellent activity, and so on. However, its mechanism(s) of actions are unclear and have not, to our knowledge, been studied to date. Previous studies suggest that the fatty acids of the ω-9, ω-6, and ω-3 series, which are present in emu oil, may act on cyclooxygenase, lipoxygenase, and lipoxin pathways to bring about its anti-inflammatory and other beneficial actions. The aim of this review was to provide a brief summary of the current knowledge of research on emu products, mainly emu oil, for the possible use as a complementary and alternative natural medicine for various chronic diseases. In this review we also highlighted the future research scope of emu oil for its possible antidiabetic activity. Thus, emu oil is an attractive pharmacologic agent to further explore for its therapeutic activity to treat various ailments.

Carcass yields and meat quality characteristics of adult emus (Dromaius novaehollandiae) transported for 6h before slaughter.

The meat quality characteristics of adult emus transported for 6h before slaughter were determined. Forty-two emus were used in two trials, undertaken under warm and cool weather conditions, respectively. Male emus had significantly higher fat yields than females (12.43kg vs 9.5kg, P=0.002). About 38.1% of the emus had no wounds or bruises, 40.5% had bruises, while 21.4% had small wounds after transport. Meat from injured emus had significantly higher pH45. In warm weather, emus experienced significantly higher loss in body weight than that under cool weather. Drip loss in meat after 24h of storage was higher in emus which had greater live weight loss after transport (r=0.66, P<0.0001), confirming the adverse effects of transport stress on meat quality. Nutrient supplementation did not significantly affect processing yield or meat quality characteristics. This study points to the need for optimizing transport conditions of emus to maintain meat quality.

Transportation stress and the incidence of exertional rhabdomyolysis in emus (Dromaius novaehollandiae).

Many emu farms are located in areas lacking processing facilities that can handle these birds. Thus, long-distance shipping of birds to an abattoir is necessary. Two experiments were conducted, wherein emus were transported in a modified horse trailer for 6 h to an abattoir. Changes in the indices of stress and metabolic homeostasis (hematology, serum biochemistry, enzymes, and body temperature and weight) were used to evaluate the physiological response to transport. The activities of enzymes alanine aminotransferase, aspartate aminotransferase, and creatine kinase increased significantly (P < 0.001) from pretransport to slaughter, indicating muscle cell wall damages. The body temperature of emus was significantly (P < 0.001) increased from 37.0 to 39.6°C after transport in experiment 1 and from 37.2 to 38.9°C in experiment 2. Transport resulted in significant weight loss in both experiments (P < 0.001; 2.1 ± 0.2 kg vs. 0.6 ± 0.2 kg) and posttransport resting at lairage led to slight regaining (P < 0.01) of BW. Oral administration of supplements before and after transport was effective in protecting against muscle damage and faster recovery of BW losses during lairage. The clinical findings were suggestive of the incidence of exertional rhabdomyolysis and thus underlined the need for careful handling and improved transport conditions of emus.

In vitro initiation of the acrosome reaction in the emu (Dromaius novaehollandiae).

1. An assessment of the efficiency of the acrosome reaction (AR) provides an important predictor of the fertilizing potential of semen and for diagnosis of the causes of infertility. A standardized protocol was therefore developed for initiation of the acrosome reaction in emu spermatozoa in vitro, and the role of CaCl2 or perivitelline membrane (PVM) proteins in determining the outcome of the reaction was investigated. 2. The acrosome reaction (assessed by FITC-PNA) was successfully induced in live spermatozoa by incubation for 2 min in NaCl-TES medium supplemented with 5 mM CaCl2. The maximum response was 32% live acrosome-reacted spermatozoa (LAR) achieved after 10 min incubation. 3. Compared to the outcome with 5 mM CaCl2 or PVM protein alone, the response was significantly better with a combination of PVM protein and CaCl2. 4. A significant variation in the percentage of LAR spermatozoa among individual males was observed. No treatment affected the percentage of dead acrosome-reacted spermatozoa. 5. The results emphasize the important role played by both PVM proteins and Ca(2+) in the in vitro initiation of the acrosome reaction.

Combinatorial treatment of tart cherry extract and essential fatty acids reduces cognitive impairments and inflammation in the mu-p75 saporin-induced mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects more than five million Americans and is characterized by a progressive loss of memory, loss of cholinergic neurons in the basal forebrain, formation of amyloid plaques and neurofibrillary tangles, and an increase in oxidative stress. Recent studies indicate that dietary supplements of antioxidants and omega-3 and omega-6 fatty acids may reduce the cognitive deficits in AD patients. The current study tested a combinatorial treatment of antioxidants from tart cherry extract and essential fatty acids from Nordic fish and emu oils for reducing cognitive deficits in the mu-p75 saporin (SAP)-induced mouse model of AD. Mice were given daily gavage treatments of Cerise(®) Total-Body-Rhythm™ (TBR; containing tart cherry extract, Nordic fish oil, and refined emu oil) or vehicle (methylcellulose) for 2 weeks before intracerebroventricular injections of the cholinergic toxin, mu-p75 SAP, or phosphate-buffered saline. The TBR treatments continued for an additional 17 days, when the mice were tested on a battery of cognitive and motor tasks. Results indicate that TBR decreased the SAP-induced cognitive deficits assessed by the object-recognition, place-recognition, and Morris-water-maze tasks. Histological examination of the brain tissue indicated that TBR protected against SAP-induced inflammatory response and loss of cholinergic neurons in the area around the medial septum. These findings indicate that TBR has the potential to serve as an adjunctive treatment which may help reduce the severity of cognitive deficits in disorders involving cholinergic deficits, such as AD.

Dietary emu oil supplementation suppresses 5-fluorouracil chemotherapy-induced inflammation, osteoclast formation, and bone loss.

Cancer chemotherapy can cause osteopenia or osteoporosis, and yet the underlying mechanisms remain unclear, and currently, no preventative treatments are available. This study investigated damaging effects of 5-fluorouracil (5-FU) on histological, cellular, and molecular changes in the tibial metaphysis and potential protective benefits of emu oil (EO), which is known to possess a potent anti-inflammatory property. Female dark agouti rats were gavaged orally with EO or water (1 ml·day(-1)·rat(-1)) for 1 wk before a single ip injection of 5-FU (150 mg/kg) or saline (Sal) was given. The treatment groups were H(2)O + Sal, H(2)O + 5-FU, EO + 5-FU, and EO + Sal. Oral gavage was given throughout the whole period up to 1 day before euthanasia (days 3, 4, and 5 post-5-FU). Histological analysis showed that H(2)O + 5-FU significantly reduced heights of primary spongiosa on days 3 and 5 and trabecular bone volume of secondary spongiosa on days 3 and 4. It reduced density of osteoblasts slightly and caused an increase in the density of osteoclasts on trabecular bone surface on day 4. EO supplementation prevented reduction of osteoblasts and induction of osteoclasts and bone loss caused by 5-FU. Gene expression studies confirmed an inhibitory effect of EO on osteoclasts since it suppressed 5-FU-induced expression of proinflammatory and osteoclastogenic cytokine TNFα, osteoclast marker receptor activator of nuclear factor-κB, and osteoclast-associated receptor. Therefore, this study demonstrated that EO can counter 5-FU chemotherapy-induced inflammation in bone, preserve osteoblasts, suppress osteoclast formation, and potentially be useful in preventing 5-FU chemotherapy-induced bone loss.

Orally administered emu oil decreases acute inflammation and alters selected small intestinal parameters in a rat model of mucositis.

Mucositis resulting from cancer chemotherapy is a serious disorder of the alimentary tract. Emu oil has demonstrated anti-inflammatory properties in animal models of arthritis and wound healing; however, its effects on the intestine remain unknown. We investigated emu oil for its potential to decrease the severity of mucositis in a rat model. Female Dark Agouti rats (110-150 g) were orogastrically gavaged with emu oil (0.5 or 1 ml) or water (1 ml) for 5 d before intraperitoneal injection of 5-fluorouracil (5-FU, 150 mg/kg) or saline (control), and this was continued up to the day of sacrifice (48, 72 and 96 h post 5-FU administration). Histological (villus height, crypt depth (CD) and disease severity score) and biochemical (myeloperoxidase (MPO) activity) parameters were determined in intestinal tissues collected at sacrifice. Sucrase activity in vivo was quantified by the sucrose breath test. Activated neutrophil activity (MPO) in the ileum was significantly decreased by emu oil (0.5 ml, 451 (sem 168) U/g and 1 ml, 503 (sem 213) U/g) compared with 5-FU-treated controls (1724 (sem 431) U/g) 96 h post 5-FU administration. There were also significant increases in CD (152 (sem 8) microm) in the ileum of rats that received 1 ml emu oil at 96 h compared with 5-FU-treated controls (CD (106 (sem 12) microm)). Emu oil did not affect sucrase activity. Emu oil decreased acute ileal inflammation, and improved mucosal architecture in the intestine during recovery from chemotherapy in rats. Further studies investigating the potential benefits of emu oil as a nutritional supplement for the treatment of intestinal disorders are indicated.

The primary structure of a novel riboflavin-binding protein of emu (Dromaius novaehollandiae).

Emu riboflavin-binding protein (RBP) was purified from egg white and yolk, and its N-terminal amino acid sequence was determined. The molecular mass of emu RBP was estimated at approximately 48 and 45 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, i.e., 10 kDa larger than chicken RBP. The molecular mass of deglycosylated RBPs indicated that the content of oligosaccharide chain in emu RBP was approximately 3 times greater than that in chicken RBP. The gene encoding the RBP precursor was cloned from emu oviduct cDNA by PCR and found also in the liver and ovary cDNAs as well as oviduct cDNA. The complete cDNA consisted of an open reading frame of 714 bp encoding a protein of 238 amino acids. The amino acid sequence deduced from the cDNA sequence revealed that many essential structural features were conserved in emu RBP including 18 cysteine residues, 2 N-glycosylation sites, a clustered phosphorylation region, and riboflavin-binding sites. Two additional potential N-glycosylation sites were found in the amino acid sequences of RBPs from the emu and other sources such as the turtle and frog, which might in part account for the greater content of oligosaccharide chain of emu RBP as compared to chicken RBP.

Interaural timing difference circuits in the auditory brainstem of the emu (Dromaius novaehollandiae).

In the auditory system, precise encoding of temporal information is critical for sound localization, a task with direct behavioral relevance. Interaural timing differences (ITDs) are computed using axonal delay lines and cellular coincidence detectors in nucleus laminaris (NL). We present morphological and physiological data on the timing circuits in the emu, Dromaius novaehollandiae, and compare these results with those from the barn owl (Tyto alba) and the domestic chick (Gallus gallus). Emu NL was composed of a compact monolayer of bitufted neurons whose two thick primary dendrites were oriented dorsoventrally. They showed a gradient in dendritic length along the presumed tonotopic axis. The NL and nucleus magnocellularis (NM) neurons were strongly immunoreactive for parvalbumin, a calcium-binding protein. Antibodies against synaptic vesicle protein 2 and glutamic acid decarboxlyase revealed that excitatory synapses terminated heavily on the dendritic tufts, while inhibitory terminals were distributed more uniformly. Physiological recordings from brainstem slices demonstrated contralateral delay lines from NM to NL. During whole-cell patch-clamp recordings, NM and NL neurons fired single spikes and were doubly rectifying. NL and NM neurons had input resistances of 30.0 +/- 19.9 Momega and 49.0 +/- 25.6 Momega, respectively, and membrane time constants of 12.8 +/- 3.8 ms and 3.9 +/- 0.2 ms. These results provide further support for the Jeffress model for sound localization in birds. The emu timing circuits showed the ancestral (plesiomorphic) pattern in their anatomy and physiology, while differences in dendritic structure compared to chick and owl may indicate specialization for encoding ITDs at low best frequencies.

Antagonism of croton oil inflammation by topical emu oil in CD-1 mice.

Emu oil is derived from the emu (Dromaius novaehollandiae), which originated in Australia, and has been reported to have anti-inflammatory properties. Inflammation was induced in anesthetized CD-1 mice by applying 50 microL of 2% croton oil to the inner surface of the left ear. After 2 h, the area was treated with 5 microL of emu, fish, flaxseed, olive, or liquified chicken fat, or left untreated. Animals were euthanized at 6 h postapplication of different oils, and earplugs (EP) and plasma samples were collected. Inflammation was evaluated by change in earlobe thickness, increase in weight of EP tissue (compared to the untreated ear), and induction in cytokines interleukin (IL)-1alpha and tumor necrosis factor-alpha (TNF-alpha) in EP homogenates. Although reductions relative to control (croton oil) were noted for all treatments, auricular thickness and EP weights were significantly reduced (-72 and -71%, respectively) only in the emu oil-treated group. IL-1alpha levels in homogenates of auricular tissue were significantly reduced in the fish oil (-57%) and emu oil (-70%) groups relative to the control group. The cytokine TNF-alpha from auricular homogenates was significantly reduced in the olive oil (-52%) and emu oil (-60%) treatment groups relative to the control group. Plasma cytokine levels were not changed by croton oil treatment. Although auricular thickness and weight were significantly correlated with each other (r = 0.780, P < 0.003), auricular thickness but not weight was significantly correlated with cytokine IL-alpha (r = 0.750, P < 0.006) and TNF-alpha (r = 0.690, P < 0.02). These studies indicate that topical emu oil has anti-inflammatory properties in the CD-1 mouse that are associated with decreased auricular thickness and weight, and with the cytokines IL-1alpha and TNF-alpha.

Influence of two dietary fats on the composition of emu oil and meat.

Male and female emus were fed a diet rich in saturated fat (beef tallow) or a diet rich in unsaturated fat (soybean oil) until they weighed about 35 kg. Samples of subcutaneous and retroperitoneal adipose tissues and samples of six major meat cuts were taken for determination of composition. Emus fed the two different diets grew at similar rates, but the male emus had a higher percentage of carcass fat. The adipose tissue cells from males were larger than those from females. All six meat cuts averaged 2.2% fat, with the regular filet having the most and the inside and outside drums the least. Cholesterol concentration of all sizes of meat cuts averaged 32.2 mg/100 g meat. Diet did not influence cholesterol content of the rendered oil. Fan filets had the greatest concentration of cholesterol, and the inside and outside drums had the least. Source of dietary fat had no effect on fat and cholesterol content of the meats. Meat from emus fed beef tallow was more tender and juicy. Fan filets were the most tender meat, had the least intense flavor, and were the most flavorful. Untrained panelists were able to discriminate between emu meat and beef. Source of dietary fat did not influence the fatty acid compositions of the meats. As expected, the soybean oil-fed emus produced oil that was more polyunsaturated than did the tallow-fed emus.

Effect of emu oil on auricular inflammation induced with croton oil in mice.

OBJECTIVE: To determine the acute anti-inflammatory effects of topically applied emu oil. ANIMALS: 96 male CD-1 mice assigned randomly to 4 groups, each comprising 24 mice. PROCEDURE: To induce auricular inflammation, 50 microl of a solution comprising 10 microl of croton oil dissolved in 1 ml of acetone was applied to the inner surface of the left auricle (pinna). One hour later, 3 or 5 microl of emu oil (low- and high-dose groups, respectively) or 5 microl of porcine oil (oil-control) was applied to the left pinna. Control mice remained untreated. Six mice per group were euthanatized 3, 6, 12, and 24 hours after induction of inflammation. Specimens of auricular tissue (ear plugs) were obtained, using a 6-mm biopsy punch. Magnitude of swelling was calculated as the weight difference between left (inflamed) and right (noninflamed) ear plugs; degree of edema was determined as the difference between wet and dry weights of the left ear plug. RESULTS: Magnitude of swelling was significantly reduced at 6 and 12 hours in mice treated with emu or porcine oil, compared with controls. The greatest reduction in swelling was detected in the high-dose emu group at 6 hours. Compared with controls, degree of edema was significantly reduced at 6 hours only in the high-dose group, whereas by 12 hours, all groups treated with oils had significantly less edema than controls. At 24 hours, magnitude of swelling and degree of edema did not differ among groups. CONCLUSION: Topically applied emu oil significantly reduced severity of acute auricular inflammation induced by croton oil in mice.