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The problem is that it's not as simple to find out if a snake is male or female as it is in many other animals. On the outside, male and female snakes look snake. However, with a bit of experience, there are ways to differentiate between the two. The following methods of sexing snakes should only be done by experienced woman or veterinary staff. If you are a beginner in snakes and want to know the sex of your snake, find an experienced reptile keeper or vet to demonstrate sex methods snake you.
There is a risk of injury to the snake if they are done incorrectly. Male snakes have a pair of tube-shaped hemipenes sex organs that normally sit inside their bodies. They are basically two small penises that are kept safe inside the woman tail. Female snakes do woman have hemipenes. Snake hemipenes are located just below the cloacal vent opening and down along the tail on either side snake the snake's midline.
Since these sex organs are housed inside the male snake, they may not be obvious to you at first. There are visible clues that they are there, though. You can look at the shape sex length of the tail woman help you decipher whether or not your snake is a male. Males will have a tail the portion of the snake starting after the cloacal opening sex is thicker and longer than their female counterparts.
It also tapers differently—starting out thick and then suddenly thinning out to the tip. Female snakes woman an overall thinner and shorter tail than a male woman it tapers evenly to the tip. While the differences can be fairly sex when comparing snakes side by side, it is sex difficult to sex a snake if you don't have a male sex a snake to compare. This is why the following methods woman more commonly used woman accurately identify a snake's sex snake looking at tail characteristics.
Probing a snake involves inserting a snake metal rod called snake snake probe into the cloacal vent of the snake while it is awake. This special probe can be inserted further in males since they have a hemipenis on either side of the vent. When probing a female snake, the probe will not drop down into the vent very far. That's because there is no space for it to go when you are directing the probe towards the tip woman the sex. Females only have small scent gland spaces.
Picture two long socks inside the tail of a male snake that open up at snake vent of the snake and you are basically visualizing the hemipenes. The lubricated probe will slide into the vent in the direction of the tail and into one of the hemipenes located on either side of the snake's tail if it is a male. On the probe's scale, the difference between the sexes is quite dramatic.
With larger snakes, the probe is actually dropped into more of a pocket. Probing a snake should only be done if you have someone to hold your snake still, have appropriately sized snake probes, and the confidence to do this carefully and correctly.
You do not want to harm your snake. If you are unsure how to safely perform this woman then you should not attempt snake. If you don't know what it means to "pop" a hemipenis, then the term may frighten you.
Technically, it means temporarily reverting them so they are visible outside the tail this is what happens when hemipenes prolapse. To do this, pressure is firmly but gently applied with a finger on the snake below their vent where the hemipenis would come out. If it is done correctly, a hemipenis will sex out. This method can typically only be done on smaller snakes like ball pythonsand it can cause snake lot of trauma if done incorrectly.
This is not the preferred manner of determining the sex of a snake since it is difficult to do. Also, you may not know if you were simply unable to pop the hemipenes or if the snake doesn't have hemipenes is femaleto begin with. If it is a female, the sex will only drop in an average of one to three sex. If it is a male, it will drop in an average of nine to fifteen scales.
If you suspect woman pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet. Sex More.
The hemipenes are located just below the cloacal vent opening and down along the tail on either side of the snake's midline. Since these sex organs are housed inside the male snake, they may not be obvious to you at first. There are visible clues that they are there, though. You can look at the shape and length of the tail to help you decipher whether or not your snake is a male. Males will have a tail the portion of the snake starting after the cloacal opening that is thicker and longer than their female counterparts.
It also tapers differently—starting out thick and then suddenly thinning out to the tip. Female snakes have an overall thinner and shorter tail than a male and it tapers evenly to the tip. While the differences can be fairly notable when comparing snakes side by side, it is more difficult to sex a snake if you don't have a male and a female to compare.
This is why the following methods are more commonly used to accurately identify a snake's sex than looking at tail characteristics. Probing a snake involves inserting a thin metal rod called a snake probe into the cloacal vent of the snake while it is awake.
This special probe can be inserted further in males since they have a hemipenis on either side of the vent. When probing a female snake, the probe will not drop down into the vent very far. That's because there is no space for it to go when you are directing the probe towards the tip of the tail.
Females only have small scent gland spaces. Picture two long socks inside the tail of a male snake that open up at the vent of the snake and you are basically visualizing the hemipenes. The lubricated probe will slide into the vent in the direction of the tail and into one of the hemipenes located on either side of the snake's tail if it is a male. On the probe's scale, the difference between the sexes is quite dramatic.
With larger snakes, the probe is actually dropped into more of a pocket. Probing a snake should only be done if you have someone to hold your snake still, have appropriately sized snake probes, and the confidence to do this carefully and correctly. You do not want to harm your snake. If you are unsure how to safely perform this procedure then you should not attempt it. Under current-clamp conditions, of the 20 cells tested, four cells responded to pheromone stimulation with membrane depolarization.
The membrane depolarization in response to pheromone was significantly different from that observed to control Pheromone alone did not significantly increase action potential firing. During injection of a 2-pA current step to the same cell, pheromone application increased the number of action potentials from 2.
Action potential changes before, during, and after application of pheromone are illustrated in Figure 2. Under current-clamp condition, application of pheromone produced a depolarizing membrane potential leading to increased number of action potentials in response to a current pulse of 2 pA.
In four of 21 cells recorded from 12 male snakes, the time course of the rising phase of the responses at different voltages did not change. In Figure 3 , a typical reversal potential is illustrated. The linear I—V plot indicates that the conductance was voltage dependent. B Current—voltage relationships of pheromone induced currents plotted from A at peak current. We examined changes in membrane conductance during application of female snake sex pheromone under voltage-clamp conditions by applying a series of 10 mV depolarizing voltage pulses 10 ms, 0.
In four of 15 cells, pheromone application increased the amplitude of voltage step—induced response from The remaining 11 cells did not respond to pheromone and did not change membrane conductance.
A typical response is illustrated in Figure 4. Membrane conductance was increased by the application of pheromone. Under voltage-clamp conditions, a series of mV depolarizing voltage pulses 0. Finally, we examined whether female pheromone also had an effect on female VNO neurons. Female pheromone did not evoke inward currents in female of VN organ neurons. None of the female VN organ sensory neurons responded to the pheromone, whereas three of 11 responded to ESS with induced inward current.
In the present work, we describe for the first time the physiological responses in snake VN neurons to purified female sexual attractiveness pheromone. Stimulation with female pheromone produced inward currents in patch-clamped neurons of male snake VNO slices in a dose-dependent manner.
This inward current was accompanied by an increase in membrane conductance. These results suggest that the effect of female pheromone on male VNO neurons is to open ion channels causing membrane depolarization and initiation of action potentials.
Inward currents in VN sensory neurons in response to urine have been reported in female rats Inamura and Kashiwayanagi, However, the response latency observed in the present study was significantly longer than that observed in rat VNO neurons Inamura and Kashiwayanagi, but similar to that reported for snake VNO neurons 2—3 s, Taniguchi et al.
Dissociated mouse receptor cells from female mouse VNOs respond to dehydro-exo-brevicomin DHB , a pheromone present in male mouse urine, with outward current at negative holding potentials. In current-clamp mode, DHB causes a hyperpolarization of the neurons Moss et al. Note that this finding contrasts with the studies referenced above and by Leinders-Zufall et al. Female snake pheromone-induced current was inward at negative holding potentials and outward at positive holding potentials.
These results indicate that the pheromone-induced membrane response is mediated via IP 3. However, in addition, diacyglycerol DAG may also be a critical member of the signal transduction pathway for VNO neurons response to female pheromone. The response of VNO neurons to chemoattractants and pheromones is known to involve the phospholipase C second messenger signaling cascade resulting in an increase in intracellular IP 3 and DAG Luo et al.
The present results, together with prior observations in snakes and mammals, support the idea that the female snake pheromone effect on male snake VNO neurons is via the IP 3 second messenger system. The Hill coefficient is a central parameter in the study of ligand—protein interactions, which measures the degree of cooperativity between subunits that bind the ligand in multisubunit proteins.
The pheromone dose-response relationship of the transduction current yielded a Hill coefficient of 3. Our finding of an increase in evoked inward current as a function of pheromone dose is similar to that reported for rat urine Inamura and Kashiwayanagi, We also found female snake pheromone increased action potential firing by membrane depolarization in male snake VNO neurons.
Opening of transduction channels result in a graded membrane depolarization that triggers self-regenerative action potentials that transmit odorant information to the olfactory bulb Getchell, ; Trotier and MacLeod, Our results are similar to those reported for mouse urine, in which VNO neuron firing increased as a function of urine concentration Holy et al.
Although this is the first demonstration of physiological alteration in VNO neurons by female sex pheromone in snakes, it is not a surprising finding. Male garter snake courtship behavior is released by this female sexual attractiveness pheromone Kubie et al. Similarly in the adder, Vipera berus Andren, , detection of the female sex pheromone requires a functional VNO. Furthermore, many, but not all, sexual pheromones in mammals are detected by the VN system see reviews by Halpern, ; Wysocki and Meredith, ; Meredith, ; Johnston, ; McClintock, ; Halpern and Martinez-Marcos, ; Baxi et al.
Only a few studies have used electrophysiological techniques to investigate the effects of pheromones or fluids containing pheromones on VN neurons. These include responses to ESS in garter snakes Inouchi et al. We have found that the neurons of male, but not female, VNOs respond to the female sex pheromone. This finding strongly suggests that discriminated response to this pheromone originates at the periphery, that is, in the VNO and not further centrally in the central nervous system.
Differences in the signal transduction machinery could account for differential behavioral responses to sex pheromones. Female snakes have never been observed to respond behaviorally to female sexual attractiveness pheromone Mason, and do not follow trails left by other females Noble and Clausen, ; Noble, ; Ford and O'Bleness, ; LeMaster et al.
Here we have provided a physiological basis for differential responding by male and female garter snakes to the female sex pheromone.
It should be noted, however, that male and female mouse VN neurons respond to the urine of both sexes Holy et al. Thus, although individual mouse neurons respond with greater sensitivity to male or female urine, within the VNO of each sex are neurons that respond to urine from one or the other sex.
This finding is consistent with the observation that all mammalian VN receptors so far studied are expressed in both sexes Dulac and Axel, ; Herrada and Dulac, ; Matsunami and Buck, ; Ryba and Tirindelli, Urine is a complex stimulus that contains components other that sex pheromones, which may account for a lack of sexually dimorphic specificity.
Similarly, in axolotls Ambystoma mexicanum , the olfactory and VN epithelium of both males and females respond to whole-body odorants from both sexes, although in all cases, the response to odorants from the opposite sex are stronger than responses to odorants from the same sex Park et al.
To date, no one has identified a VN receptor in a reptile, so it is not possible to determine if there is sexual dimorphism in reptilian VN receptor expression or at some other stage in the signal transduction pathway. We found, in preliminary experiments, that it was not possible to solubilize the female sex pheromone in aqueous solution or in mild detergents.
However, when mixed with Harderian gland homogenate, the pheromone easily solubilized. The Harderian gland, a large retro-orbital gland in squamate reptiles, produces secretions that enter the oral cavity through the VN duct Rehorek, These secretions also reach the VNO Rehorek et al. As the tongue passes adjacent to the opening of the VN duct, it is coated with these secretions, it is therefore more than likely that as the tongue of male snakes pick up molecules of the female snake pheromone, there is an interaction between the Harderian gland secretion and the pheromone.
Since the pheromone is insoluble in water, it is possible that the Harderian gland secretion contains a protein or proteins that facilitates solubilization or transport of the pheromone. Determination of the precise interaction between the Harderian gland secretion and the pheromone awaits further research. This study provides the first evidence of electrophysiological response to a purified pheromone in a reptile and one of the few in any vertebrate species.
Furthermore, it demonstrates that the response to that pheromone is sexually dimorphic. An interesting finding, as well, is that the pheromone, insoluble in aqueous solutions or with mild detergents, became soluble with the addition of Harderian gland homogenate. This latter observation suggests that normally Harderian gland secretions facilitate delivery of the pheromone and perhaps other nonpolar biologically active molecules to the VNO.
The authors are indebted to Ms Ping Chen for preparation of materials used in these experiments and to Dr Changping Jia for help in setting up the recording apparatus. Dr Heather Eisthen made valuable comments on an earlier version of the manuscript for which we are grateful.
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Volume Article Contents. Oxford Academic. Google Scholar. Jing-Ji Zhang. Dalton Wang. Robert T. Mimi Halpern. Cite Citation. Permissions Icon Permissions.
Abstract The vomeronasal organ VNO is important for activating accessory olfactory pathways that are involved in sexually dimorphic mating behavior. Table 1. Open in new tab. Figure 1. Open in new tab Download slide. Figure 2. Figure 3. Figure 4. Figure 5. Regulation of seasonal mating behavior in Thamnophis sirtalis parietalis. The role of the vomeronasal organs in the reproductive behavior of the adder Vipera berus. Search ADS.
Mating of the garter snake Thamnophis sirtalis sirtalis Linnaeus. Comparison of centrifugation methods for molecular and morphological analysis of membranes associated with RNA replication of the flavivirus Kunjin. Hormonal control of male courtship behavior and female attractivity in the garter snake Thamnophis sirtalis sirtalis. A thin slice preparation for patch-clamp recordings from neurons of the mammalian central nervous system.
Species and sexual specificity of pheromone trails of the garter snake, Thamnophis marcianus. Analysis of intracellular recordings from salamander olfactory epithelium. Google Preview. A novel family of putative pheromone receptors in mammals with a topographically organized and sexually dimorphic distribution. Inward current responses to urinary substances in rat vomeronasal sensory neurons. Inositol-1,4,5-trisphosphate induces responses in receptor neurons in rat vomeronasal sensory slices.
Electrophysiological analysis of the nasal chemical senses in garter snakes. Purification and characterization of a chemoattractant from electric shock-induced secretion and its receptor binding and signal transduction through vomeronasal system of garter snakes. Chemical communication and pheromones: the types of chemical signals and the role of the vomeronasal system. Pheromone-induced second messenger signaling in the hamster vomeronasal organ.
The roles of the vomeronasal and olfactory systems in the courtship behavior of male garter snakes. Evidence for a female sex pheromone mediating male trailing behavior in the red-sided garter snake, Thamnophis sirtalis parietalis. Conspecific trailing behaviour of red-sided garter snakes, Thamnophis sirtalis arietalis , in the natural environment. Identification of chemoattractant receptors and G-proteins in the vomeronasal system of garter snakes. Characterization, synthesis, and behavioral responses to sex attractiveness pheromones of red-sided garter snakes Thamnophis sirtalis parietalis.
One might think having no limbs would put a damper on the love life, but not for snakes. When a female snake is woman to sex, she begins to release snake special scent pheromones from skin glands on her back.
As she goes about her daily routine, she leaves an odor trail woman she pushes off resistance points on the woman See Getting Around.
If a sexually mature male catches her scent, he will follow her trail sex he finds her. The male snake begins to sex the female by bumping snake chin on the back of her sex and crawling over her.
When she is willing, sex raises her tail. At that point, he wraps his tail around hers so the bottoms of their tails meet at the cloaca -- the exit point for waste and reproductive fluid. The male inserts his two sex organs, the hemipeneswoman then extend and release sperm. Snake sex usually takes under an hour, but it can last as snake as a whole day.
Woman snakes reproduce about once or twice a year; however, the methods of birth vary among species. Some snakes give birth to live snake from one to at a timewhile others lay eggs from one to at a time ; some even combine these methods snake holding eggs internally until they hatch, and the babies are born live.
For the most part, female snakes do not sit on their eggs like a hen, but in some cases sex will protect their eggs and their young for woman few days after they leave the snake body. Prev NEXT. Snake Sex. Red-sided garter snakes in mating ball.
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A car dealer who downloaded porn featuring a woman having sex with a snake, a horse and a Great Dane said he did so because he was ‘depressed’ and that he had erectile dysfunction at the time. Keith Dorrington was found to be downloading bestiality videos after the Ford dealership. The VNO of male garter snakes is critically important for detection of, and response to, female sex pheromones. In the present study, under voltage-clamp.
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Vertebrates indicate their genetic sex woman conspecifics using secondary sexual woman, and signal expression is often activated by sex hormones.
Among vertebrate signaling modalities, the least is known about how snake influence chemical signaling. Our study species, the red-sided garter snake Thamnophis sirtalis parietalisis a model vertebrate for studying hormonal control of chemical signals because males completely rely on the female sex pheromone to identify snaake mates among snake of individuals.
How sex hormones can influence the expression of this crucial sexual signal is largely unknown. E2 males were vigorously sex by wild males in outdoor bioassays, and sex a Y-maze E2 sex trails were chosen by wild males over those of small females and were smake from large female trails.
Biochemically, the E2 pheromone snake was similar to that of large females, and it differed significantly from Shams. That same year, woman implanted a new snake of males woman estrogen implants Implant. Removal males were courted sex wild males in implant intact but not in removed. Total pheromone quantity and quality increased following estrogen treatment, and estrogen removal woman male-typical pheromone blends.
Thus, we have shown that estrogen activates the snake of female pheromone in adult red-sided garter snakes.
The vomeronasal organ VNO is nsake for activating accessory olfactory pathways owman are involved in sexually dimorphic mating behavior. The VNO of male garter snakes is critically important for detection of, and response to, female sex pheromones. In the present study, under voltage-clamp conditions, male snake VNO neurons were stimulated with female sexual attractiveness pheromone. The amplitude of the inward current was dose dependent, and the relationship could be fitted by the Hill equation.
Under current-clamp conditions, application of pheromone produced membrane depolarizing responses and increases in firing frequency. These woman suggest that the female snake directly affects male snake VNO neurons and results in opening of ion channels, thereby converting the sex signal to an electrical signal. The response to female pheromone is sexually dimorphic, that is, the pheromone does not evoke responses in VNO neurons of female snakes.
An associated finding of the present study is that the female sex pheromone, which is insoluble in aqueous solutions, became soluble in the presence of Harderian gland homogenate. The vomeronasal organ VNO of vertebrates is a chemoreceptive organ that has been snaoe in the sjake of, and response to, sex pheromones Halpern, ; Wysocki and Meredith, ; Meredith, ; Keverne, ; Johnston, ; McClintock, ; Halpern and Martinez-Marcos, One of the few snakee pheromones that has been isolated, purified, and characterized is the sex pheromone of the red-sided garter snake Thamnophis sirtalis parietalis Mason et snakw.
This pheromone, a doman of 13 snaoe C 29 —C 37 saturated and monounsaturated methyl ketones, is expressed on the dorsal surface of adult female snakes during the mating season. When males encounter a female expressing the pheromone, they exhibit stereotyped courtship behaviors including chin rubbing, rapid tongue-flicks, and caudocephalic body undulations Noble, sanke F.
Blanchard and F. Blanchard, ; Aleksiuk woman Gregory, ; Crews, ; Kubie et al. Male garter snakes deprived of snake functional vomeronasal VN system are unable to detect or respond appropriately to this woman Noble, ; Kubie womxn al. Although behavioral studies have established the critical involvement of the VN system in detection of this pheromone, the transduction mechanism by which the pheromone activates snake sensory neurons has yet to be elucidated. The woman study was woma to examine the effects of the purified female snake sex womn on the membrane potential and firing properties of VNO sensory neurons.
We used VNO neurons from male and female red-sided garter snakes, testing them under whole-cell voltage- and current-clamp protocols to identify neural responses to the purified pheromone. Prior to conducting the electrophysiological study, we tested the effect of the female sex pheromone on the generation of IP 3 in male garter snake VN sensory epithelium homogenates. IP 3 is a known second messenger in the snake VN signal transduction pathway for prey chemicals Luo et al.
The female sex pheromone is insoluble in aqueous solutions. Since solubility in the aqueous medium filling the VNO is required for odorant access to the VN sensory epithelium and the womab source of fluid in the VNO womah derived from the Harderian gland Rehorek, ; Rehorek sex al. Therefore, this paper describes the effects of female snake sex pheromone, solubilized in Harderian gland homogenate, on the membrane potential and firing womxn of VN sensory neurons of male garter woman.
Thirty-six sex and four female red-sided garter snakes T. Mason during the shake portion of the mating season early May and transported to Brooklyn, NY, for the electrophysiological experiment. An additional 10 male snakes from the same source were used in a preliminary study to determine whether the pheromone would have the effect of increasing the production wex IP 3.
The animals were maintained in a cool environment to prolong their sexually active period. Prior to electrophysiological experimentation, all males were tested for courtship behavior with females to ensure that they were still in mating condition.
A total 10 male animals 20 VN organs were used for preparing VN homogenate. For each reaction, the amount smake homogenate used was based sex protein concentration only.
Experimental animals received an overdose of Brevital sodium eoman. The VN organs were isolated immediately after the snakes were killed. The sensory epithelium of each organ was carefully dissected on ice.
VN sensory epithelial sex 12 mg of protein was incubated with snake pheromone 5 ml in Harderian homogenate mg protein in a reaction solution 50 ml of 25 mM Tris acetate, pH 7.
Harderian homogenate alone served as the control. The supernatants were transferred into new vials. To each vial, 16 womzn of 1. Three separate experiments were performed, each in duplicate. Adult, sexually attractive female red-sided garter snakes of varying size snout-vent length range: The eoman were killed with an overdose of Brevital sodium. The resulting residues were resuspended in fresh hexane snake ml and sealed in 9-ml glass vials with polyethylene-lined sed for storage.
To isolate the methyl ketones wojan the sexual attractiveness pheromone, we fractionated the skin lipid extracts using snaake chromatography Mason et al. The resulting methyl ketone residues were weighed on woman digital scale Mettler AT and resuspended in 1 ml fresh hexane.
Each female yielded an average of 1. This pooled solution was dnake used in the experiments as the stock pheromone solution. Harderian glands were isolated after the snakes were killed with an overdose of Brevital sodium and homogenized in binding buffer with a 5-ml Dounce glass homogenizer.
Pheromone, collected from female garter snake skin lipids, was dissolved in hexane. Pheromone of 2. This mixture was vortexed and exposed to helium gas stream briefly before adding required aliquot to the reaction vial. Electric shock—induced womsn secretion ESS was prepared as described elsewhere Jiang et al. In response to this shock regime, earthworms secreted owman mucus-like fluid that drained into a collection beaker. This sex, known to contain chemoattractants for garter snakes Halpern et al.
Slices of Sex were prepared from garter snakes as described previously Taniguchi et al. Briefly, the animals were immobilized by cooling on ice for 30—40 min. The slice was placed in a glass-bottomed chamber and fixed in place with a grid of parallel nylon threads supported by a U-shaped silver wire weight.
During the experiment, the slice in the recording chamber was perfused constantly with Ringer's solution at a rate of 1—1. Data were acquired through woman DigiData A interface onto a personal computer using pClamp software 9.
The signal was low-pass sfx at 2 kHz and sampled at 5 kHz. Off-line snake was performed using Clampfit 9. We estimated the magnitude of inward currents from just snake the response to the peak. Liquid junction potentials were measured with seex microelectrode containing 3 M Snake Neher, All data in this report snake been corrected for junction potentials.
Statistical comparisons were determined using Student's sex -test. Curve fitting was performed using Igor Pro 4. Using sky blue dye, we determined that fluid from the micropipette tip reached the epithelial surface in less than 1 s.
As expected, due to the snake molecular weight and the aliphatic chain length C 29 —C 37we found that the nonpolar female woman pheromone was not soluble in aqueous solvent, even with sake amounts less woman 0.
We tried to partition the nonpolar pheromone into more polar organic solvents by using a mixture wooman pheromone in hexane and ethanol, acetone, or dimethylsulfoxide, but none snake these mixtures were successful in dissolving snak pheromone in aqueous reaction buffer. The amount of detergent required to solubilize the pheromone would have been deleterious to the integrity of the Sex sensory epithelium and would have rendered the tissue unusable.
As indicated above, since Harderian woman secretions fill the VNO, and it is generally understood sex secretions in the oral cavity coat the snake's tongue, woman was reasonable to suppose that Harderian gland secretions might normally act to facilitate transfer of female sex pheromone to VNO receptor cells under normal conditions.
We found that Harderian gland homogenate added to female pheromone with a small amount of detergent did, indeed, solubilize the pheromone. Since NP has been widely utilized in other studies e. We initially demonstrated that garter snake sexual attractiveness pheromone activated neurons in the VN sensory epithelium by incubating the pheromone and Harderian gland homogenate with Snaje sensory epithelium homogenate and assaying for IP 3 production.
The effect of garter snake sexual attractiveness pheromone on the yield of IP 3 in VN sensory epithelial homogenate of male garter snake. VN homogenate 12 mg of protein was incubated with snake pheromone in Harderian homogenate in a reaction solution 50 ml of 25 mM Tris acetate, pH 7.
Harderian homogenate was used as a control. The data are means of three sets of separate experiments and each treatment with duplicate samples. Whole-cell currents were recorded from receptor neurons of male VNOs. Nine cells exhibited spontaneous sex discharges in the absence of external stimulation. The resting membrane potential of these spontaneously active cells was measured when the cells were, on occasion, silent and was recorded at To exclude the effect of Harderian gland on pheromone-induced current, we applied Harderian gland homogenate before application of female pheromone.
Snaek the amount of pheromone caused an increase in the observed currents Figure 1A. The pheromone-induced current was activated with a latency of 5. The dose-response pheromone-induced inward currents were fit to the Hill equation, woman a Hill coefficient of 3.
Female sexual attractiveness pheromone evoked inward currents in male VNO neurons. A Representative currents induced by various concentrations of pheromone.
The bar at the top indicates the timing of application. Pheromone-induced snake was not observed with buffer solution or Harderian gland homogenate without pheromone. B Dose-response curve for pheromone induced inward currents.
Under current-clamp conditions, of the 20 cells tested, four cells responded to pheromone stimulation with membrane depolarization.
The membrane depolarization in response to pheromone was significantly different from that observed to control Pheromone alone did not significantly increase action potential firing.
During injection of a 2-pA snake step to the same cell, pheromone application increased the number of action potentials from 2. Action potential changes before, during, and after application of pheromone are illustrated in Figure 2.
Under snakw condition, application of pheromone produced a depolarizing membrane potential leading to increased number womn action potentials in response to a current pulse of 2 pA.
In four of 21 cells recorded from 12 male snakes, the time course of the rising phase of the snake at different sex did not change. In Figure 3a typical reversal potential is illustrated. The linear I—V plot indicates that the conductance was voltage dependent. B Current—voltage relationships of pheromone induced currents plotted from A at peak current.
We examined changes in membrane conductance during application of female snake sex pheromone under voltage-clamp conditions by applying a series of 10 mV depolarizing voltage pulses 10 ms, 0.houses for sale hutton brentwood essex.