Scientists have identified neurons that relay temperature information from sensory fibres in the spinal cord to the thermoregulatory control centre in the brain, reports a study in the January 2008 issue of Nature Neuroscience. This neural pathway transmits temperature information to the brain regions that produce physiological changes to defend the body against the effects of low temperatures.
Kazuhiro Nakamura and Shaun Morrison used two types of tracers in rats to identify an area in the brainstem containing neurons that receive information from temperature sensory fibres and then send this information to the central thermoregulatory control area. These neurons, in a part of the brain called the lateral parabrachial nucleus, increased their activity in response to skin cooling. Blocking the activity of the neurons abolished shivering, metabolic and cardiac responses to cooling, while stimulating the neurons produced these protective responses. Physiological responses to cooling persisted when the pathway mediating temperature perception was disrupted, suggesting that the two pathways are distinct.
Kazuhiro Nakamura (Oregon Health & Science University, Beaverton, OR, USA)
Abstract available online.
(C) Nature Neuroscience press release.
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