The cellular localization of 5-HT2A receptors in the spinal cord and spinal ganglia of the adult rat

Abstract

The localization of serotonin2A (5-HT2A) receptors in the adult rat spinal cord and dorsal root ganglia was examined by using a polyclonal antibody that recognizes the C-terminus peptides of the mouse 5-HT2A receptor. Positive cell bodies of 5-HT2A receptor were found in several regions of the spinal cord. Generally, large-to-intermediate sized neuronal cell bodies were intensely immunolabeled. Motoneurons in the ventral horn were the most intensely labeled. Dot-like immunoreactive profiles were located beneath the cell membrane of motoneurons. Neuronal somata in the intermediolateral nucleus of the thoracic spinal cord were moderately labeled. The immunoreactivity in the dorsal horn was weak. A considerable number of glial cell bodies in the white matter were immunostained. The majority of both small and large sized neurons were 5-HT2A immunopositive in the dorsal root ganglion.

Pharmacological characterization of serotonin receptor subtypes modulating primary afferent input to deep dorsal horn neurons in the neonatal rat

“…This low frequency may be explained in relation to the relatively small percentage of 5-HT 2A/2C receptors present in the dorsal horn of the rat (Pompeiano et al, 1994;Maeshima et al, 1998;Cornea-Hebert et al, 1999). The facilitation observed here is consistent with a facilitation of evoked excitatory synaptic responses in nearly 50% of dorsal horn neurons tested with higher concentrations of DOI (10 mM) reported by Hori et al (1996).…”

Central serotonin system indystonia musculorum mutant mice: Biochemical, autoradiographic and immunocytochemical data

“…Indeed, large decreases in specific binding to 5-HT 3 receptors as well as smaller decreases in specific binding to 5-HT 1A and 5-HT 1B receptors have been reported after dorsal rhizotomy, and also following neonatal capsaicin treatment in the case of the 5-HT 3 receptor (Kidd et al, 1993;Laporte et al, 1995). Likewise, since 5-HT 2A receptors have been identified immunocytochemically in a majority of both small and large sized neurons in rat dorsal root ganglion (Maeshima et al, 1998) (Dewar et al, 1992;Hyttel et al, 1984;Pranzatelli and Martens, 1992 Marec et al, 1998;Strazielle et al, 1996). In both these mutants, the cerebellar cortex and the deep cerebellar nuclei are atrophied, but the densities of [ 3 H]citalopram binding are increased in the deep cerebellar nuclei even after correction for their reduced volume.…”

Development of Autonomic Dysreflexia after Spinal Cord Injury Is Associated with a Lack of Serotonergic Axons in the Intermediolateral Cell Column

“…Of the many serotonin receptor subtypes identified (Barnes and Sharp, 1999), the 5-HT 1A and 5-HT 2A receptors appear to play a role in regulating blood pressure (Coote, 1990;Lewis and Coote, 1990;Yusof and Coote, 1986). In the spinal cord, the 5-HT 1A receptor is found predominantly in the superficial laminae of the dorsal horn (Barnes et al, 1999), whereas the 5-HT 2A receptor is robustly expressed in motor neurons in the ventral horn, and SPNs in the IMLC and lamina X (Doly et al, 2004;Maeshima et al, 1998). In contrast, neurons in the superficial laminae of the dorsal horn exhibited only weak and diffuse expression of 5-HT 2A receptors (Doly et al, 2004;Maeshima et al, 1998).…”