Hi Karin, You could use passive infrared transponder (PIT) tags that include a temperature sensor injected under the skin to measure subcutaneous body temperature (a couple of companies make these) - the drawback is that you need to scan the mouse with a reader within about 5 cm to obtain a reading. The alternative is to implant radio transmitters that include a temperature sensor, usually in the peritoneal cavity. With fm transmitters, temperature information is transmitted via changes in pulse (beep) rate (detected using a standard telemetry receiver potentially with a datalogger), whereas a few companies have am frequency transmitters that require unique receiver plates (but have the advantage of much longer battery life). Hope this helps.

Best wishes, Chris

Hi Karin, You could use passive infrared transponder (PIT) tags that include a temperature sensor injected under the skin to measure subcutaneous body temperature (a couple of companies make these) - the drawback is that you need to scan the mouse with a reader within about 5 cm to obtain a reading. The alternative is to implant radio transmitters that include a temperature sensor, usually in the peritoneal cavity. With fm transmitters, temperature information is transmitted via changes in pulse (beep) rate (detected using a standard telemetry receiver potentially with a datalogger), whereas a few companies have am frequency transmitters that require unique receiver plates (but have the advantage of much longer battery life). Hope this helps.

Best wishes, Chris

I've been looking at these sensors lately:

http://www.star-oddi.com/products/43/tiny-temperature-sensor/default.aspx

The systems are reasonably priced (depending on your budget!), the sensors are small, and multiple sensors can be implanted, theoretically, in a single animal--an advantage over some of the competing systems.

Those Star-Oddi loggers look interesting. Does anyone have any experience with them? We need something small and durable for implanting into free-ranging animals.

I second Chris Turbill's recommendation of the PIT tags, we've used them in small rodents and they work very well. However, you cannot put multiple tags in the same animal, or get a reading from more than one at once.

Mini mitter works quite well in a laboratory setting.

Just stay far, far away from modifying iButtons.

Thank you for your answers! Indeed we had been looking into implantable sensors, but the problem as far as I understood for us now is that we house the animals in an individual cages Phenomaster system (TSE), and this would require special adaptations in order to being able to get the sensors in close enough proximity to the implanted sensors to obtain signals. Thus I was hoping, since it seems that we will not spend any budgets on upgrades like this in the near future, if there was also a way to for example make rectal temperature measurements more standardized and thus comparable (for example measuring twice consecutively, or on consecutive days).

Thank you for your input!

Good morning,

There are some data loggers (Thermochron Ibutton) that have been used in mice, rats and degus for core body temperature recordings during long periods. Here you have the methodology in some examples

Otalora BB, Madrid JA, Alvarez N, Vicente V, Rol MA. (2008). Effects of exogenous

melatonin and circadian synchronization on tumor progression in melanoma-bearing

C57BL6 mice. J Pineal Res. 44:307-315.

Lax P, Otalora BB, Esquiva G, Rol MA, Madrid JA, Cuenca N. (2011). Circadian

dysfunction in P23H rhodopsin transgenic rats: effects of exogenous melatonin. J

Pineal Res. 50: 183-191.

Vivanco P, Otalora BB, Rol MA, Madrid JA.(2010). Dissociation of the circadian system

induced by T28 and T21 LD cycles in Octodon degus. Chronobiol Int. 27:1580-1595.

I hope it could help you.

Best

Antonio

Hey Antonio, great, thank you! So, do I understand the system directly that you don't need to transmit the data real time, but can implant animals with the devices (where in the body?), and then remove them and retrieve data (over a how long measurement period) later on?

Many thanks,

Karn

Hi Karin,

Yes you are right. You implant the sensors. They log during 2048 data in those examples (I know others with 4096 data) implanted in the abdominal cavity. And then you remove the sensors and download the data.

You can change the sample rate from 1 to 255 min (at least) and they have different models according to a variety of specs.

Thanks to you and good luck

Antonio

I forgot it!

Here you have the Maxim's web page with a comparative between different iButtons

http://para.maximintegrated.com/search.mvp?fam=ibutton&142=Temperature%20Data%20Logging&1028=Temperature

Best,

Antonio

Thank you! So, the sample rate means that this is the maximal recording time that the device can store?

Best,

Karin

I think I didn't explain it properly... Sorry

The loggers maximal recording time is dependent of the sample rate and they record 2048 or 4096 data. So, If we take a measure each hour we'll have 2048 or 4096 hours of maximal recording time (85 or 170 days, respectively) while if the sample rate is 10 minutes we'll have 341 or 682 hours (14.2 and 28.4 days).

I hope I explain it better than previously

Best,

Antonio

Oh wow, sorry for not understanding it before, now everything is clear, thank you a lot! This is great! :)

Best,

Karin

Wonderful!

I wish you the best for your research :)

Antonio

Hi Karin and Antonio,

Just a quick note on iButtons, they are rather large for mice (~3g). Although it is possible to lessen the weight by removing the outer casing (see Lovegrove, B. G. (2009). Modification and miniaturization of Thermochron iButtons for surgical implantation into small animals. J. Comp. Physiol. B 179, 451-458.) this seriously increases the chance of the logger malfunctioning and you losing all the data. You can get smaller, and apparently reliable, miniaturized versions of iButtons (WeeDrop) from Alpha-Mach but they are significantly more expensive.

Thank you, Danielle! In fact, our animal surgon approached me yesterday with the concern that the devices are too big for our mice. So, you would not suggest to follow the method in this paper, did you try it and experience malfunctioning of the devices afterwards?

Hi,

It is true Danielle and Karin. The Ibuttons are too big (15% of the mouse's weight). However, Otalora BB implant these devices with good results and without problems with the mice. I've not personal experience whit this topic. Maybe you can ask her. She is in Researchgate.

I would only suggest it as a last resort. It didn't work out very well for me, apparently they've changed something in the manufacturing process since that paper came out that makes the modification less reliable. The problem is if the circuit board gets disconnected from the battery you lose all of the data. Apparently if you solder the connection there is less of a chance of this happening. We used glue instead with very poor results.

Hope this helps.

I see, thanks a lot, Danielle! I will keep it in mind then, but will seek for other alternatives.

You can consider to use the VitalView Data Acquisition System. The transmitter suitable for your experiment named G2 E-mitter with a mass of only 1.1g.

The most convenient side of this system is that the transmitter is battery free, so theoretically it can record as long time as possible. The resolution and accuracy is quite good. Aside from the body temperature, you can also got the gross activity data at the same time.

Dear Karin, there are several methods to do this in a Phenomaster environment. Remember that during a metabolic study the animals cannot and should not be removed from their cages and that Humans should not enter the room for any longer periods of time since their CO2 exhasust will compromise the experiment. Rectal temperature is therefore not an option. Having said that there are 2 telemetry solutions. One is an injectable small RF implant like minimitter (Phenomaster add-on via TSE)  that records temperature and sends these to an antenna under the cage. The nice thing about this system is that the temperature data are captured in the Phenomaster software. The second option is  a full blown STELLAR telemetry implant for physiological monitoring (Temp but also ECG, Pressure etc.). Here you do not need an antenna per cage. Just one in the room. http://www.tse-systems.com/products/implantable-telemetry/animal-telemetry-system.htm .  cheers, HJK , TSE Bad Homburg.

Hi, I am writing a systematic review on this; the protocol is online at CAMARADES (http://www.dcn.ed.ac.uk/camarades/files/SYRCLEProtocolFormat_v2.pdf), and I should have finished the review for normothermic mice in a few months. I don't see that anyone has mentioned temperature-sensing microchips here-- have a look at http://www.bmds.com/uploads/files/IPTT300.pdf. For intermittent body temperature measurement, these seem to work well.

I don't have much experience with this but could you anesthetize the mice so that they don't sense the probe and get stressed? There may be changes in temp with anesthesia  which would be worth checking.

When you anesthetize the mouse, the temperature will drop very fast.

Hi, I have done a systematic review of this but haven't published the results yet. In addition to microchips (which work well short-term but may degrade with time), you might consider a skin surface probe (YSI makes one), which causes less stress than taking the temperature with a rectal probe. The method you use may depend on whether you are interested in absolute body temperatures, or relative trends in temperature between groups. You also must consider what the expected temperature difference is, and make your choice based on the precision required to differentiate between the test and control groups.

Hi, I've developed a system named Anipill. It's an implantable device small enough to be implanted in mice (up to 20gr). Temperature data are collected in real time (accuracy 0.1°C) and sent using Radio protocol. After implantation, the system can work during up to 1 year. There is no artifact between devices and animals can live all together. Sterile and biocompatible, the system is not stressful for the animal since you don't need any contact. Already validated and used in published studies.

Sébastien

Dear Sébastien,

I'd love to see the published studies, and add them to my systematic review!

Janet

Dear Janet,

The study recently published by Tortensall et al used this system :

Tattersall GJ, Roussel D, Voituron Y, Teulier L. 2016 Novel energy-saving strategies to multiple stressors in birds: the ultradian regulation of body temperature.

Proc. R. Soc. B 283: 20161551.

http://dx.doi.org/10.1098/rspb.2016.1551

You will also find Validation studies on my Profile:

Article: Performance testing of an innovative telemetric temperature sensor in animals

P.-A. Chapon · N. Bessot · A. Gauthier · [...] · S. Moussay

Full-text available · Article · Jun 2013 · Journal of Thermal Biology

Article: Calibration and performance assessment of a temperature sensor prototype using a 1-point calibration procedure

P A Chapon · A Gauthier · J Bulla · S Moussay

Full-text available · Article · Nov 2012 · The Review of scientific instruments

Don't hesitate to contact me for further information.

Sébastien

A rectal thermometer may be considered in rats and mice.