Focal hemorrhagic stroke in the left or right rat posterior insular cortex results in equipotent changes in sympathetic activity (686.11)

Abstract

Evidence suggests that unilateral damage to the insular cortex(IC) leads to autonomic imbalance and cardiovascular (CV) dysfunction. We evaluated the CV effects from focal hemorrhage (ICH) into the left (L) or right (R) IC. Wistar rats were anesthetized for microinjection of autologous arterial blood (ICH) or saline (200nL, n=10 each side/group) into the L or R IC (0mm AP/ ±5.8mm LL/ 7mm DV). After 24 hours, mean arterial pressure (MAP) and heart rate (HR) were measured in awake condition. Then, ICH and control group (n=7 each side) were anesthetized and renal sympathetic activity (RSNA) was record. ICH increased baseline HR (Δ:L‐ICH 471±8 vs saline 407±7bpm; R‐ICH 465±8 vs saline 408±5bpm, P<0.05) without changing MAP. HR was restored to baseline levels after i.v. atenolol injection (2mg/kg). Strikingly, ICH rats presented a reduced baseline RSNA (Δ:L‐ICH 112±5 vs saline 148±7spikes/sec; R‐ICH 121±4 vs saline 149±10spikes/sec, P<0.05). There were no differences between L‐ and R‐ICH. We conclude that focal stroke into posterior IC can alter the cardiac and renal autonomic control without lateral predominance. These findings can help to understand the cardiac and renal dysfunctions observed after cortical damage. Grant Funding Source: CNPq, Fapemig, Capes and INCT NanoBioFar