- Email: [email protected]
Effects of a unilateral lesion in the locus coeruleus on cerebral vasomotor response
270
greater postural fall in mean blood pressure, than age-matched controls. These findings suggest that low plasma renin activity and readily decreasing blood pressure may contribute to the difficulty some children have in waking up in the morning. If these children have trouble at school in the morning, they may need treatment for orthostatic dysregulation, since the present findings in children with difficulty in waking up in the morning are similar to those previously found in children with difficulty in waking up in the morning as a symptom of orthostatic dysregulation. (The Autonomic Nervous System, 27: 319-324, 1990)
Effects of a unilateral lesion in the locus coeruleus on cerebral vasomotor response Yoshihito Nakazato Department of Neurology, Saitama Medical School, Saitame, Japan
The locus coeruleus innervates cerebral intraparenchymal blood vessels; its role in the cerebral vasomotor responses has been investigated in the present study. Twelve monkeys were anesthetized with alpha-chloralose and urethane. PaCO 2 and body temperature were kept within the physiological range. Internal carotid blood flow was measured continuously and bilaterally with electromagnetic flowmeters, simultaneously with blood pressure and pulse rate. An electrode was stereotaxically placed into the locus coeruleus of one side and an electrolytic lesion was produced (100V, 0.8 mA, 1 min). Cerebral vasomotor responses were compared before and after lesioning the locus coeruleus, by means of the autoregulatory index ( A I C B F / A M A B P , m l / m i n / m m Hg) and the chemical vasomotor index ( A I C B F / A P a C O 2 , m l / m i n / m m Hg). 1. Systemic blood pressure and cerebral hemodynamics. Following lesion of the locus coeruleus, blood pressure fell, but there were no significant changes in the internal carotid blood flow of the ipsi- or contralateral side. 2. Cerebral vasomotor responses. The autoregulatory response to the hypotension induced by hemorrhage was reduced in the side contralateral to the lesion (p < 0.05), and the response to the hypertension induced by infusion of blood was reduced on the ipsilateral side (p < 0.05). The chemical vasomotor response to hypocapnia induced by passive hyperventilation was reduced on the contralateral side (p < 0.05), whereas the response to hypercapnia induced by 7% CO 2 inhalation was not significantly different between the two sides. From these data, it can be suggested that the locus coeruleus modulates cerebral vasomotor responses. (The Autonomic Nervous Systems 27: 329-337, 1990)
Electrophysiologicai activity in preganglionic fibers of the superior cervical ganglion after experimental subarachnoid hemorrhage Shinichi Takahashi Department of Neurology, School of Medicine, Tokyo, Japan
The purpose of the present study was to clarify the role of the noradrenergic nervous system in the pial artery vasospasm after subarachnoid hemorrhage. Thirteen cats were anesthetized with alpha-chloralose and urethane and were artificially ventilated. Preganglionic fibers to the superior cervical ganglion were severed close to the ganglion. Action potential discharges were recorded from the preganglionic nerve
greater postural fall in mean blood pressure, than age-matched controls. These findings suggest that low plasma renin activity and readily decreasing blood pressure may contribute to the difficulty some children have in waking up in the morning. If these children have trouble at school in the morning, they may need treatment for orthostatic dysregulation, since the present findings in children with difficulty in waking up in the morning are similar to those previously found in children with difficulty in waking up in the morning as a symptom of orthostatic dysregulation. (The Autonomic Nervous System, 27: 319-324, 1990)
Effects of a unilateral lesion in the locus coeruleus on cerebral vasomotor response Yoshihito Nakazato Department of Neurology, Saitama Medical School, Saitame, Japan
The locus coeruleus innervates cerebral intraparenchymal blood vessels; its role in the cerebral vasomotor responses has been investigated in the present study. Twelve monkeys were anesthetized with alpha-chloralose and urethane. PaCO 2 and body temperature were kept within the physiological range. Internal carotid blood flow was measured continuously and bilaterally with electromagnetic flowmeters, simultaneously with blood pressure and pulse rate. An electrode was stereotaxically placed into the locus coeruleus of one side and an electrolytic lesion was produced (100V, 0.8 mA, 1 min). Cerebral vasomotor responses were compared before and after lesioning the locus coeruleus, by means of the autoregulatory index ( A I C B F / A M A B P , m l / m i n / m m Hg) and the chemical vasomotor index ( A I C B F / A P a C O 2 , m l / m i n / m m Hg). 1. Systemic blood pressure and cerebral hemodynamics. Following lesion of the locus coeruleus, blood pressure fell, but there were no significant changes in the internal carotid blood flow of the ipsi- or contralateral side. 2. Cerebral vasomotor responses. The autoregulatory response to the hypotension induced by hemorrhage was reduced in the side contralateral to the lesion (p < 0.05), and the response to the hypertension induced by infusion of blood was reduced on the ipsilateral side (p < 0.05). The chemical vasomotor response to hypocapnia induced by passive hyperventilation was reduced on the contralateral side (p < 0.05), whereas the response to hypercapnia induced by 7% CO 2 inhalation was not significantly different between the two sides. From these data, it can be suggested that the locus coeruleus modulates cerebral vasomotor responses. (The Autonomic Nervous Systems 27: 329-337, 1990)
Electrophysiologicai activity in preganglionic fibers of the superior cervical ganglion after experimental subarachnoid hemorrhage Shinichi Takahashi Department of Neurology, School of Medicine, Tokyo, Japan
The purpose of the present study was to clarify the role of the noradrenergic nervous system in the pial artery vasospasm after subarachnoid hemorrhage. Thirteen cats were anesthetized with alpha-chloralose and urethane and were artificially ventilated. Preganglionic fibers to the superior cervical ganglion were severed close to the ganglion. Action potential discharges were recorded from the preganglionic nerve