Serotonin receptor and dendritic plasticity in the spinal cord following chronic serotonergic pharmacotherapy combined with exercise following complete SCI in the adult rat.

Serotonin receptor and dendritic plasticity in the spinal cord following chronic serotonergic pharmacotherapy combined with exercise following complete SCI in the adult rat. Exp Neurol. 2018 Mar 08;: Authors: Ganzer PD, Beringer CR, Shumsky JS, Nwaobasi C, Moxon KA Abstract Severe spinal cord injury (SCI) damages descending motor and serotonin (5-HT) fiber projections leading to paralysis and serotonin depletion. 5-HT receptors (5-HTRs) subsequently upregulate following 5-HT fiber degeneration, and dendritic density decreases indicative of atrophy. 5-HT pharmacotherapy or exercise can improve locomotor behavior after SCI. One might expect that 5-HT pharmacotherapy acts on upregulated spinal 5-HTRs to enhance function, and that exercise alone can influence dendritic atrophy. In the current study, we assessed locomotor recovery and spinal proteins influenced by SCI and therapy. 5-HT, 5-HT2AR, 5-HT1AR, and dendritic densities were quantified both early (1 week) and late (9 weeks) after SCI, and also following therapeutic interventions (5-HT pharmacotherapy, bike therapy, or a combination). Interestingly, chronic 5-HT pharmacotherapy largely normalized spinal 5-HTR upregulation following injury. Improvement in locomotor behavior was not correlated to 5-HTR density. These results support the hypothesis that chronic 5-HT pharmacotherapy can mediate recovery following SCI, despite acting on downregulated spinal 5-HTRs. We next assessed ...
Source: Experimental Neurology - Category: Neurology Authors: Tags: Exp Neurol Source Type: research