Identification of the spinal pathways involved in the recovery of baroreflex control after spinal lesion in the rat using pseudorabies virus
| Autor: | Matthew R. Zahner, Deborah G. Castillo, Lawrence P. Schramm |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Adrenergic Neurons
Sympathetic nervous system Sympathetic Nervous System Time Factors Physiology Autonomic Fibers Preganglionic Pseudorabies Baroreflex Kidney Rats Sprague-Dawley Lesion Physiology (medical) Animals Medicine Spinal cord injury Neural Control Staining and Labeling biology business.industry Rostral ventrolateral medulla Spinal cord biology.organism_classification medicine.disease Herpesvirus 1 Suid Rats medicine.anatomical_structure Spinal Cord Anesthesia Female medicine.symptom business Neuroscience Brain Stem |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 303:R590-R598 |
| ISSN: | 1522-1490 0363-6119 |
| DOI: | 10.1152/ajpregu.00008.2012 |
| Popis: | Neurons in the rostroventrolateral medulla (RVLM) mediate baroreflex regulation (BR) of spinal sympathetic preganglionic neurons. Previously, our laboratory has shown that recovery of BR occurs in the rat after spinal hemisection. (Zahner MR, Kulikowicz E, and Schramm LP. Am J Physiol Regul Integr Comp Physiol 301: R1584–R1590, 2011). The goal of these experiments was to determine whether the observed recovery of BR is mediated by the reorganization of ipsilateral pathways or by compensation by spared contralateral pathways. To determine this, we infected the left kidney in rats with the retrograde transynaptic tracer, pseudorabies virus (PRV), either 1 or 8 wk after left spinal hemisection at either T3 or T8, or after a sham lesion. In sham-lesioned rats, PRV infection of RVLM neurons was bilateral. In all rats with a left hemisection, regardless of the location of the lesion (T3 or T8) or postlesion recovery time (1 or 8 wk), PRV infection of left RVLM neurons was significantly reduced compared with sham-lesioned rats ( P < 0.05). In a separate group of rats, we performed BR tests by measuring responses of left renal sympathetic nerve activity to pharmacologically induced decreases and increases in arterial pressure. In rats with T8 left hemisection and 8-wk recovery, BR was robust, and acute right upper thoracic hemisection abolished all BR of left renal sympathetic nerve activity. Collectively, these data suggest that the recovery of BR is not mediated by reorganization of ipsilateral bulbospinal connections, but instead by improved efficacy of existing contralateral pathways. |
| Databáze: | OpenAIRE |
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