Mucin-like glycopolymer gels in electrosensory tissues generate cues which direct electrolocation in amphibians and neuronal activation in mammals

Mucin-like glycoproteins have established roles in epithelial boundary protection and lubricative roles in some tissues.This mini-review illustrates alternative functional roles which rely on keratan sulphate and sialic acid modifications to mucin glycopolymers which convey charge properties suggestive of novel electroconductive properties not previously ascribed to these polymers.Many tumour cells express mucin-like glycopolymers modified with highly sulphated keratan sulphate and sialic which can be detected using diagnostic biosensors.The mucin-like keratan sulphate glycopolymer present in the ampullae of lorenzini is a remarkable sensory polymer which elasmobranch fish(sharks,rays,skate) use to detect weak electrical fields emitted through muscular activity of prey fish.Information on the proton gradients is conveyed to neuromast cells located at the base of the ampullae and mechanotransduced to neural networks.This ampullae keratan sulphate sensory gel is the most sensitive proton gradient detection polymer known in nature.This process is known as electrolocation,and allows the visualization of prey fish under conditions of low visibility.The bony fish have similar electroreceptors located along their lateral lines which consist of neuromast cells containing sensory hairs located within a cupula which contains a sensory gel polymer which detects distortions in fluid flow in channels within the lateral lines and signals are sent back to neural networks providing information on the environment around these fish.One species of dolphin,the Guiana dolphin,has electrosensory pits in its bill with similar roles to the ampullae but which have evolved from its vibrissal system.Only two terrestrial animals can undertake electrolocation,these are the Duck-billed platypus and long and short nosed Echidna.In this case the electrosensor is a highly evolved innervated mucous gland.The platypus has 40,000 electroreceptors around its bill through which it electrolocates food species.The platypus has poor eyesight,is a nocturnal feeder and closes its eyes,nostrils and ears when it hunts,so electrolocation is an essential sensory skill.Mammals also have sensory cells containing stereocilia which are important in audition in the organ of corti of the cochlea and in olfaction in the olfactory epithelium.The rods and cones of the retina also have an internal connecting cilium with roles in the transport of phototransduced chemical signals and activation of neurotransmitter release to the optic nerve.Mucin-like glycopolymer gels surround the stereocilia of these sensory hair cells but these are relatively poorly characterized however they deserve detailed characterization since they may have important functional attributes.

Experimentally investigating the effect of buccal acupuncture on analgesic time-effect characteristics and monoamine neurotransmitters

Objective： To investigate the analgesic time-effect characteristics and changes in concentrations of rabbit＇s hypothalamic 5-hydroxytryptamine （5-HT） and noradrenaline （NE） caused by buccal acupuncture in the rheumatoid arthritis （RA） rabbits, and to reveal the analgesic central mechanism of buccal acupuncture, thereby providing a theoretical basis for the treatment of pain by buccal acupuncture. Methods： Forty rabbits were randomly divided into a normal group, a model group, a body acupuncture group, and a buccal acupuncture group, with 10 rabbits in each group. No model was established in the normal group, while equal dose of normal saline was injected at the matched site and time point; rabbits in other groups were subjected to the establishment of RA models using egg protein. From the 27th day of the experiment, rabbits in each group received the designated intervention. Rabbits in the normal group and the model group were fixed for 30 min every day using the same method as those in the other groups. In the acupuncture group, Dubi （ST 35） and Zusanli （ST 36） on bilateral hind limbs were selected. Perpendicular needling （using the needles with 0.25 mm in diameter and 25 mm in length） was performed with twirling manipulation for 15 s at intervals of 5 min. The needles were retained for 30 min and acupuncture was performed once a day. In the buccal acupuncture group, the knee point in the buccal acupuncture and needles with a diameter of 0.25 mm and a length of 15 mm were selected. Oblique needling was performed with twirling manipulation for 15 s at intervals of 5 min. The needles were retained for 30 min and acupuncture was performed once a day. The thermal pain thresholds at the O, 5, 15, 30, 60, 120 and 240 rain after the 1st and 10th acupuncture therapy were measured with a PL-200 thermal-inducing pain meter. After the 10th acupuncture therapy, rabbit＇s hypothalamus was removed, and the 5-HT and NE concentrations in the hypothalamus at the peak point of the acupuncture pain threshold curve were determined by high performance liquid chromatography （HPLC）. Results： The analgesic effect was obvious at 5 min after buccal acupuncture started, peaked at 30 min, and decreased to the lowest value at 240 rain. Rabbits in the body acupuncture group began to show significant analgesic effect at 15 min, which was peaked at 30 min, and began to decline at 60 min. The pain threshold at 240 min was still higher than that at 0 mino Compared with the model group, the concentrations of hypothalamic 5-HT in the buccal acupuncture group and the body acupuncture group was significantly increased, and the between-group differences were statistically significant （both P〈0.05）. The NE/5-HT ratios in hypothalamus in the buccal acupuncture group and the body acupuncture group were significantly lower than the ratio in the model group, and the differences were statistically significant （both P〈0.05）; difference in the decrease was statistically significant between the buccal acupuncture group and the body acupuncture group （P〈0.05）. Conclusion： The analgesic effect of buccal acupuncture shows an obvious time-dependent curve. It is characterized by rapid onset of pain relief, rapid increase and decline in pain threshold. 5-HT and NE levels in rabbit＇s hypothalamus can be affected by buccal acupuncture, with increased 5-HT concentration and reduced NE/5-HT rati0.

Effects of electroacupuncture on the behaviors and expressions of hippocampal neurotransmitters and Bax/Bcl-2 proteins in rat models of anxiety disorder

Objective:To investigate the effects of electroacupuncture(EA)on the behaviors of rat with anxiety disorder,and the expressions of hippocampal neurotransmitters including 5-hydroxytryptamine(5-HT),norepinephrine(NE)and dopamine(DA),and the expressions of hippocampal B-cell lymphoma-2(Bcl-2)and Bcl-2 associated X(Bax).Methods:Forty-six male Wistar rats were randomly divided into a control group(n=10);a model group(n=12),an EA group(n=12),and a drug group(n=12).Except the control group,the other three groups were established into rat models of anxiety disorder using uncertain empty bottle stimulation.Rats in the EA group and the drug group received corresponding interventions for 15 consecutive days[EA group was given EA at Baihui(GV 20)and Sanyinjiao(SP 6);the drug group was given aqueous solution of alprazolam via intragastric administration].After intervention,all four groups received open-field test(OFT)and elevated plus-maze(EPM)for behavioral evaluations.The expressions of 5-HT,NE and DA in hippocampus were determined by fluorescence spectroscopy(FS)while the expressions of Bcl-2 and Bax proteins in hippocampus were determined by Western blot(WB).Results:The OFT horizontal scores in the control group,EA group and drug group were significantly higher than that in the model group(all P<0.05),and the difference between the EA group and the drug group was statistically insignificant(P>0.05);the OFT vertical scores in the model group,EA group and drug group were significantly lower than the score in the control group(all P<0.05).The EPM percent of open-arm entries(OE%)in the control group,EA group and drug group was higher than that in the model group(P<0.05),and the differences among these three groups were statistically insignificant(P>0.05);though the percent of open-arm total time(OT%)in the EA group was lower than that in the control group(P<0.05);the difference was statistically insignificant when compared with the drug group(P>0.05),and it was significantly higher than that in the model group(P<0.05).The expression of 5-HT in the EA group was higher than that in the control group(P<0.05);the expression of 5-HT in the EA group was significantly lower than that in the model group(P<0.05);the difference between the EA group and the drug group was statistically insignificantly(P>0.05).The expression of NE in the model group was significantly higher than that in the other three groups(P<0.0S),and there was no significant difference among these three groups(P>0.05).The expression of DA in the EA group was significantly higher than that in the control group and the drug group(both P<0.05),while the difference between the EA group and the model group was statistically insignificant(P>0.05).The expression of Bax in the model group was significantly higher than that in the other three groups(all P<0.05),whereas the expression of Bcl-2 in the model group was significantly lower than that in the other three groups(all P<0.05),and the differences in both Bax and Bcl-2 among the other three groups were statistically insignificant(all P>0.05).Bax/Bcl-2 in the EA group was significantly higher than that in the control group(P<0.05)and lower than that in the model group(P<0.05),and the difference was statistically insignificant when compared with the drug group(P>0.05).Conclusion:EA shows promising effects in attenuating rats'anxiety disorder,which may be achieved by the down-regulation of the expressions of 5-HT and NE in the hippocampus and/or inhibition of hippocampal neuronal apoptosis.The efficacy is comparable to that of intervention with alprazolam.