Functional mapping of the cardiorespiratory effects of dorsal and median raphe nuclei in the rat

The dorsal (DRN) and median (MRN) raphe nuclei are important sources of serotonergic innervation to the forebrain, projecting to sites involved in cardiovascular regulation. These nuclei have been mapped using electrical stimulation, which has the limitation of stimulating fibers of passage. The present study maps these areas with chemical stimulation, investigating their influence on cardiorespiratory parameters. Urethane-anesthetized (1.2 g/kg, iv) male Wistar rats (280-300 g) were instrumented for pulsatile and mean blood pressure (MBP), heart rate, renal nerve activity, and respiratory frequency recordings. Microinjections of L-glutamate (0.18 M, 50-100 nl with 1 percent Pontamine Sky Blue) were performed within the DRN or the MRN with glass micropipettes. At the end of the experiments the sites of microinjection were identified. The majority of sites within the MRN (86.1 percent) and DRN (85.4 percent) evoked pressor responses when stimulated (DRN: deltaMBP = +14.7 ± 1.2; MRN: deltaMBP = +13.6 ± 1.3 mmHg). The changes in renal nerve activity and respiratory rate caused by L-glutamate were +45 ± 11 and +42 ± 9 percent (DRN; P < 0.05 percent), +40 ± 10 and +29 ± 7 percent (MRN, P < 0.05), respectively. No significant changes were observed in saline-microinjected animals. This study shows that: a) the blood pressure increases previously observed by electrical stimulation within the raphe are due to activation of local neurons, b) this pressor effect is due to sympathoexcitation because the stimulation increased renal sympathetic activity but did not produce tachycardia, and c) the stimulation of cell bodies in these nuclei also increases the respiratory rate.

Síndrome de Shy-Grager: relato de um caso clínico / Shy-Drager syndrome: case report

A síndrome de Shy-Drager é uma doença degenerativa do sistema nervoso central, de etiologia desconhecida, caracterizada por falência progressiva do sistema autonômico e atrofia de múltiplos sistemas. É relatado o caso de uma paciente do sexo feminino que aos 41 anos de idade foi estabelecido o diagnóstico de síndrome de Shy-Drager. Provas funcionais autônomas, exames laboratoriais e exame físico, principalmente minucioso exame neurológico, evidenciaram claramente a falência do sistema nervoso autônomo e sinais de atrofia multissistematizada. Seräo ressaltados aspectos clínicos-evolutivos que caracterizaram os 8 anos da enfermidade, de investigaçäo da funçäo autonômica e de diagnóstico diferencial - já que a doença foi confundida durante a fase inicial com outras enfermidades sistêmicas e do sistema nervoso