In situ hybridization autoradiography

Autoradiography, in situ hybridization, western blot analysis, and immunohistochemical studies have described the distribution of sigma receptors in the brain (Samovilova et al., 1985 Largent et al., 1986 Jansen et al., 1991 Bouchard and Quirion, 1997 Alonso et al., 2000 Zamanillo et al., 2000). The al receptor is expressed in septum, olfactory bulb, hypothalamus, anterodorsal thalamic nucleus, dorsal raphe, locus coeruleus, substantia nigra, and the cerebellum. 

The distribution of cannabinoid receptors has been extensively mapped by quantitative autoradiography, in situ hybridization, and immunocytochemistry. Each of these techniques has its strengths and weaknesses. Properly calibrated, quantitative autoradiography provides the best measure of absolute receptor density. Nonetheless, its spatial resolution is limited and specificity depends on the ligand used. In situ hybridization identifies the cells synthesizing CB i mRNA. However, mRNA levels and protein levels may not necessarily correlate. Immunocytochemistry provides outstanding spatial resolution however, fixation artifacts and unanticipated antibody crossreactivity must be assiduously avoided. For the most... 

Lopez-Gimenez, J. F., Vilaro, M. T., Palacios, J. M. Mengod, G. (2001). Mapping of 5-HT2a receptors and their mRNA in monkey brain [3H]MDL100,907 autoradiography and in situ hybridization studies. J. Comp. Neurol. 429, 571-89. 

Landwehrmeyer B., Mengod G., Palacios J. Differential visualization of dopamine D2 and D3 receptor sites in the rat brain. A comparative study using in situ hybridization histochemistry and ligand binding autoradiography. Eur. J. Neurosci. 5 145, 1993. 

Abstract Quantitative receptor autoradiography methods have heen widely used over the last three decades to study the distribution and physiological role of a receptor in various tissues. This review provides an overview of in vivo and in vitro receptor autoradiography methods and their advantages as well as disadvantages in the study of receptors in the central nervous system. Comparison with immuno-histochemical and in situ hybridization methods is also highlighted in relation to the study of a given receptor in the nervous sytem. 

Mengod G, Vilaro MT. 1993. Analysis of receptor expression by in situ hybridization histochemistry. Receptor autoradiography principles and practice. Wharton J, Polak JM, editors. Oxford, England Oxford University Press pp. 159-170. 

Zhao W, Truettner J, Schmidt-Kastner R, Belayev L, Ginsberg MD. 1999. Quantitation of multiple gene expression by in situ hybridization autoradiography accurate normalization using Bayes classifier. J Neurosci Meth 88 63-70. 

Mengod G, Vilaro MT, Raurich A, Lopez-Gimenez JF, Cortes R, Palacios JM. 5-HT receptors in mammalian brain receptor autoradiography and in situ hybridization studies of new ligands and newly identified receptors. Histochem J 1996 28 747-758. 

Key Words Serotonin 5-HT receptor subtypes receptor autoradiography radioligands mRNA in situ hybridization histochemistry immuno-histochemistry. 

Palacios JM, Mengod G, Hoyer D. Brain serotonin receptor subtypes radioligand binding assays, second messengers, ligand autoradiography, and in situ hybridization histochemistry. Methods Neurosci 1993 12 238-261. 

Westlake TM, Howlett AC, Bonner II, Matsuda LA, Herkenham M. 1994. Cannabinoid receptor binding and messenger RNA expression in human brain An in vitro receptor autoradiography and in situ hybridization histochemistry study of normal aged and Alzheimer s brains. Neuroscience 63 637-652. 

In contrast to studies on Di and D2 receptors, due to the relative lack of selective D3 drugs the majority of studies on D3 receptor distribution have been performed with in situ hybridization rather than with receptor binding autoradiography. 

The localization of DiB and D5 receptors by receptor binding autoradiography has been hampered by the lack of high affinity DiB/5 specific ligands. Therefore, in situ hybridization studies of the receptor mRNA and immunohistochemical studies with specific anti-D1B/5 antibodies have been used to map the distribution of D1B/5 receptors in the rat, monkey and human brain (Niznik et al., 2003). 

Nicot A, Rostene W, Berod A (1994) Neurotensin receptor expression in the rat forebrain a combined analysis by in situ hybridization and receptor autoradiography. J Comp Neurol 347407 119. 

---