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title: In vivo - non-invasive
disqus: hackmd
---
:::success
> Documentation [name=MrDr.Staffan]
###### tags: `non-invasive`

### Table of Contents
[TOC]
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[Top](#Table-of-Contents)

*Why this page?*
If you poke any particular region of the brain, you can get a response in the body. this is how brain-body plans where traditionally investigated.

With todays sofisticated measuring methods the question then becomes. Can this also be utilized the other way? If we see movement in a body part, can we from that infeer the activity in a particlar part of cortex? The studies where they interpret brain signals from after listening to a song - suggests this might be the case.

If so detailed recording of external ques can tell a large amount about what activity is going on inside the brain.

Movement, temperature, general behaviour, specific behaviours and drives, thirst eating, pre-eating, etc. These are all vague estimates but togheter and using AI could provide useful measures, to be correlated to in situ mechanisms.

*Questions for this page*
"Do shaking-off stress - reset pre-synaptic acetylcholine stores?"
"what is the reason our nose get easily cold?"

# Temperature
Temperature is spatially restricted - [and blood vessles tend to follow similar pattern as vasculature? Blood and nerves go hand-in-hand?]

## PET/MRI temperature measurements?
Can this data be collected? Spatial? Inside outside?
In humans the BAT would be measured above claviture. The nose which tends to be cold when stressed? This ratio might be of interest to investigate the
https://pubmed.ncbi.nlm.nih.gov/31301122/

## Infrared thermography
Infrared radiation is emitted naturally from any object with a temperature higher than zero. The relationship between the infrared radiation and the surface temperature of an object is expressed by the Stephen–Boltzmann formula, using an ideal object called a black body. The radiation ratio of a black body is equal to 1.0.

however, when infrared thermography is performed on an animal, the radiation ratio of its body surface is estimated by matching the temperature recorded by an **infrared thermometer** to that obtained by a **contact thermometer**.

Importantly, infrared thermography is non-invasive and contactless, allowing the animals to move freely without any disturbance during temperature measurement, which makes this method completely animal-friendly and particularly suitable for behavioral research.

In the case of rodents, the temperature of the interscapular region is commonly used for measurement purposes.

[This in effect measures BAT temperature][If BAT activation can be seen as compensatory for maintaining overall body temp. then this is an excellent measure of total energy expenditure.][If eyes, or nose (as I know from histamines) at all can be used to estimate brain temperature the difference between scapular nose is indeed very interesting.][Do complex aa, inhibit temperature generation in cells also. Can I prove this. and relate this to cellular/ mitochondrial function. then i have a paper.][Is nose-brain better correlated than nose-body?]

To obtain accurate measurements, it is best to **remove the hair** of the animals by shaving or use nude mice, as, although hair does not produce heat, it can maintain it (Fiebig et al., 2018)

Angle?
Since radiation travels in straight lines, measuring the intensity of thermal radiation using an acute angle reduces the radiation received. Therefore, although continuous long-term thermographic recording is feasible and can be applied to freely moving wild animals (Vinne et al., 2020), this angle dependency may result in data variability.
[Does this mean that whole body recordings (which could compensate for body movement - muscle generated heat?)]

[Otherwise, nose/eye temperature adjusted for BAT expenditure and muscle use. Should be an excellent measure of brain energetics.]

### Aversion, social
[Infrared thermography for non-invasive measurement of social inequality aversion in rodents and potential usefulness for future animal-friendly studies](https://www.frontiersin.org/articles/10.3389/fnbeh.2023.1131427/full#:~:text=Infrared%20thermography%20is%20a%20method%20that%20detects%20thermal,body%20surface%20temperature%20of%20animals%20from%20a%20distance.)

### Bulls eye
[Infrared thermography as a non-invasive method for detecting fear-related responses of cattle to handling procedures](https://www.cambridge.org/core/journals/animal-welfare/article/abs/infrared-thermography-as-a-noninvasive-method-for-detecting-fearrelated-responses-of-cattle-to-handling-procedures/9AA2CBE6001E18A3B4452DFFD9389E65)
M Stewart , AL Schaefer , DB Haley , J Colyn , NJ Cook , KJ Stafford and JR Webster

Two experiments were conducted to determine whether maximum eye temperature, measured using infrared thermography (IRT), could be a non-invasive technique for detecting responses of cattle to handling procedures.

Experiment one used six crossbred heifers randomly assigned to two groups in a crossover design and subjected to i) being hit with a plastic tube on the rump and ii) being startled by the sudden waving of a plastic bag.

Maximum eye temperature was recorded continuously pre- and post-treatment. In experiment one, eye temperature dropped rapidly between 20 and 40 s following both treatments and returned to baseline between 60 and 80 s following hitting and between 100 and 120 s following startling.

Boissy, A, Manteuffel, G, Jensen, MB, Moe, RO, Spruijt, B, Keeling, LJ, Winckler, C, Forkman, B, Dimitrov, I, Langbein, J, Bakken, M, Veissier, I and Aubert, A 2007 Assessment of positive emotions in animals to improve their welfare. Physiology and Behavior

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