Formalin hindpaw injection induces changes in the [3H]prazosin binding to α1-adrenoceptors in specific regions of the mouse brain and spinal cord

Abstract

Involvement of the alpha1-adrenoceptor subtypes in early and late phases of formalin pain was investigated by quantitative in vitro autoradiography in the spinal cord and brain structures of CD-1 mice. Total alpha1-adrenoceptors binding (including all alpha1-adrenoceptor subtypes) was assessed with [3H]prazosin; alpha(1B)-adrenoceptor was assessed with [3H]prazosin in the presence of 10 nM WB4101 to mask remaining alpha1-adrenoceptor subtypes. Early after formalin injection the alpha1-adrenoceptors (mainly alpha1B receptor) binding was reduced in the contralateral hind limb area of the somatosensory cortex and in the secondary motor cortex. A reduction occurred also in the ipsilateral laminae I-III of the spinal cord (both alpha1B- and non-alpha1B-adrenoceptors). Lately an increase of alpha1-adrenoceptors binding (mostly subtypes other than alpha1B) appeared in discrete amygdaloid and thalamic nuclei. These results provide the first description of changes at the level of central alpha1-adrenoceptors' binding during the formalin-induced pain in mice. Their distribution suggests that they may have a functional meaning.

Effect of Antidepressant Drugs in Mice Lacking the Norepinephrine Transporter

“…Quantitative autoradiography was carried out as described by Nalepa et al (2005) and Strazielle et al (1999). After decapitation, mice brains were rapidly removed, frozen, and stored on dry ice.…”

Stimulation of α1-adrenoceptors reduces glutamatergic synaptic input from primary afferents through GABAA receptors and T-type Ca2+ channels

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A Review on in Vivo and in Vitro Experimental Models to Investigate the Anti-Inflammatory Activity of Herbal Extracts

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