5-Hydroxytryptamine2C receptors on spinal neurons controlling penile erection in the rat
Section snippets
Animals and tissue preparation
Adult male Sprague–Dawley rats weighing 250–300 g (Centre d'Elevage Janvier, France) were maintained under standard conditions (22–24°C: 12/12 h light/dark cycle, food and water ad libitum). All efforts were made to minimize animal suffering and to reduce the number of animals used.
Rats were anaesthetized with pentobarbital (50 mg/kg, i.p.) and perfused via the ascending aorta (flow rate 20 ml/min) with 100–150 ml of 0.9% (w/v) NaCl containing sodium nitrite (1 g/l), followed by 650 ml of 4%
Distribution of 5-hydroxytryptamine2C receptor immunoperoxidase labelling at the L5–S1 levels of the spinal cord
At low magnification, the distribution of 5-HT2C receptor immunoreactivity revealed by the ABC method using DAB as a chromogen was homogeneously distributed within the gray matter of the L5–S1 segments of the spinal cord (Fig. 1). The overall distribution was similar at all levels of the spinal cord (not shown). However, slight differences were noticed in the different areas of gray matter at the lumbosacral level. A more intense labelling was found in the intermediolateral column of the L6 and
Evidence for 5-hydroxytryptamine2C receptors in the rat L5–S1 spinal cord
The localization of 5-HT2C receptors in the lumbosacral spinal cord has been described using anti-peptide antibodies directed against the carboxy-terminal part of the rat receptor. These antibodies have been previously characterized in detail and their specificity assessed using Western blotting experiments and cell transfection studies.2 The distribution of 5-HT2C receptor immunoreactivity in the spinal cord closely matched that of 5-HT2A–2C binding sites labelled by [125
Conclusion
The distribution of 5-HT2C receptor immunoreactivity in the lumbosacral spinal cord of the rat was consistent with that of the corresponding mRNA and binding sites.30., 43. Numerous neurons were intracellularly labelled, at the level of the Golgi apparatus, particularly in the SPN and the DGC. The immunocytochemical detection of 5-HT2C receptors combined with pseudo-rabies virus transsynaptic retrograde transport demonstrated that neurons in the SPN and the DGC contributing to the innervation
Acknowledgements
This work was supported by the “Centre National de la Recherche Scientifique” (CNRS) and the “Ministère de l'Education nationale, de la Recherche et de la Technologie”. We thank the Institut Jacques Monod and the CHU Saint-Louis for providing confocal laser scanning microscope facilities. Ms M.-J. Brisorgueil is gratefully acknowledged for expert technical assistance, and V. Setola for reading the manuscript.
References (45)
- et al.
Neuroendocrine and behavioral effects of m-chlorophenylpiperazine administration in rhesus monkeys
Life Sci.
(1984) - et al.
Generation of anti-peptide antibodies against serotonin 5-HT2A and 5-HT2C receptors
J. Neurosci. Meth.
(1997) - et al.
Drug-induced penile erections in rats: indications of serotonin1B receptor mediation
Eur. J. Pharmac.
(1987) - et al.
Parasympathetic preganglionic neurons in the sacral spinal cord
J. auton. Nerv. Syst.
(1982) - et al.
Preganglionic neurons in the sacral spinal cord of the rat: an HRP study
Neurosci. Lett.
(1979) - et al.
Autoradiographic mapping of 5-HT1, 5-HT1A, 5-HT1B and 5-HT2 receptors in the rat spinal cord
Brain Res.
(1991) - et al.
Lesions of the nucleus paragigantocellularis alter ex copula penile reflexes
Brain Res.
(1992) - et al.
Serotonergic neurotoxic lesions facilitate male sexual reflexes
Pharmac. Biochem. Behav.
(1994) - et al.
Central nervous system innervation of the penis as revealed by the transneuronal transport of pseudorabies virus
Neuroscience
(1993) - et al.
Stimulation of spinal serotonergic receptors facilitates seminal emission and suppresses penile erectile reflexes
Brain Res.
(1985)