Open AccessEffect of stimulation of sublobule IX-b of the cerebellar vermis over cardiac function
Author(s) -
Isabel Rocha,
Victor Gonçalves,
Maria João Bettencourt,
L Silva-Carvalho
Publication year - 2008
Publication title -
physiological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.647
H-Index - 70
eISSN - 1802-9973
pISSN - 0862-8408
DOI - 10.33549/physiolres.931262
Subject(s) - medicine , ventricle , cardiac function curve , afterload , cardiology , blood pressure , stimulation , anesthesia , aorta , cardiac output , bradycardia , cerebellar vermis , heart rate , anatomy , heart failure , cerebellum
Activation of sublobule IX-b of the cerebellar vermis evokeshypotension, bradycardia and decrease of the phrenic nerveactivity in the anesthetized animal. Cardiac performance duringthe isovolumic phases of systole and relaxation can be evaluatedby dP/dtmax, Vpm, dP/dt/DP40 and τ, respectively. In the presentstudy, we evaluated the changes on cardiac function evoked bythe stimulation of sublobule IX-b. New Zealand white rabbitswere anesthetized, paralyzed and artificially ventilated. Aposterior craniotomy was made to reveal and stimulate thecerebellar uvula (4 s train; 50 Hz; 1 ms; 20 μA). The femoralartery and veins were cannulated and a Swan-Ganz catheter wasadvanced in the upper abdominal aorta to control afterload wheninflating the balloon. The left ventricle was catheterized with aMillar catheter. Blood pressure, heart rate, left ventricularpressure were monitored. Results showed a significant decreaseon sublobule IX-b stimulation of all the indices of systolic functionand an increase of τ indicating a decrease in the speed of therelaxation. These data provide the first evidence of the influenceof sublobule IX-b on cardiac function. They may contribute to theunderstanding of the origin the cardiovascular changes that wereobserved in two patients with vermian and paravermianhemorrhage.