Menthol

[modest]

Right, but that is talking about reception as well. I'm curious about reaction. In other words, all these articles talk about certain receptors that relay the perception of cold or hot. Menthol activates the 'cold' sensors, while capsaican activates the 'warm' receptors. These messages travel through the nervous system to our brain (brain stem?) and are unconsciously regulated. The brain senses cold in, say, the fingertips. Bloodflow is increased and lots of other chemical signals are given. If the initial reactions are not enough, your body will naturally convulse, or shiver, to produce heat (via increased blood flow).

 

Now, my question is: Are the receptors fooled into provoking this type of response by "imitators" such as menthol?

 

Oh, I see. wiki's Thermoregulation says the hypothalamus controls temperature, but nothing in the way of real details.

 

One thing I've noticed is that goose bumps (goose pimples) can be localized to the area where I'm exposed to cold. For instance, reaching in a cold freezer will cause them on whichever arm is doing the reaching. I doubt goose bumps are related to core body temp at all then. Vasodilation also seems like it can be a reaction to feeling cold stimuli. Shivering seems more related to core temperature. But, I don't know. We'd have to find something about the neurology of thermoregulation.

 

~modest

[freeztar]

Good show. For the purpose of this thread, I think that vasodilation would be a sufficient indicator. Yes/no?

[Nitack]

MB, you have presented some great support for the notion that menthol does not actually change the temperature but simply tricks the cold receptors in our skin. I still have some unanswered questions though. I am re posting the abstract for the study from my second post.

 

Menthol and nicotine oppositely modulate body temperature in the rat

 

David N. Ruskina, Corresponding Author Contact Information, E-mail The Corresponding Author, Rene Anandb and Gerald J. LaHostea

aDepartment of Psychology, University of New Orleans, New Orleans, Louisiana, USA bNeuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA

 

Abstract

 

Menthol is a prominent additive in many tobacco products. To investigate possible interactions with nicotine, (−)-menthol (200 or 400 mg/kg) and (−)-nicotine (0.5 mg/kg) were injected subcutaneously in rats, and body temperature, which is modulated by brain nicotinic acetylcholine receptors, was measured. Nicotine caused robust (− 1.6 °C) hypothermia, the magnitude and time course of which was not altered by menthol pretreatment. Menthol alone produced mild (0.4–0.8 °C) hyperthermia, which was not secondary to locomotor activation. Nicotine and menthol influence body temperature independently and oppositely; menthol does not appear to influence the function of the central nicotinic receptors that control body temperature.

 

Keywords: Nicotinic acetylcholine receptor; α4 subunit; Core temperature; Hypothermia

 

If this study showed that menthol in fact did produce a temperature change, doesn't that contradict or call into question the findings of some of the other studies?

 

Hyperthermia, in its advanced state referred to as heat stroke or sunstroke, is an acute condition which occurs when the body produces or absorbs more heat than it can dissipate.

 

;)