Arterioles are major contributors to the control of systemic blood pressure and local blood flow. In this study, we compared electrophysiological properties of vascular smooth muscle cells (VSMCs) in anterior inferior cerebellar artery (AICA), mesenteric artery (MA) and spiral modiolar artery (SMA) by intracellular microelectrode recording and whole-cell patch clamp recording techniques. Results were shown as below: (1) Intracellular microelectrode recordings were made from VSMCs in AICA, MA and SMA with resting potentials of (-68±1.8) (n=65), (-71±2.4) (n=80) and (-66±2.9) mV (n=58), respectively. There was no significant difference in resting potentials among arterioles. (2) The membrane capacitance and membrane conductance in situ cells were much larger than those in dispersed smooth muscle cells by whole-cell recording techniques, and there was significant difference among arterioles, which were in the order: MA>AICA>SMA. After application of gap junction blocker 2-APB (100 μmol/L), the membrane capacitance and membrane conductance in situ cells were very close with those in single smooth muscle cells. (3) The I/V relation of whole-cell current of dissociated smooth muscle cells (AICA, MA and SMA) showed a prominent outward rectification, and the currents were substantially inhibited by 1 mmol/L 4-AP or 10 mmol/L TEA. When the command voltage was +40 mV, the current densities of VSMCs in AICA, MA and SMA were (26±2.0), (24±1.7) and (18±1.3) pA/pF respectively. SMA showed significant difference in the current density from AICA and MA respectively. These results suggest that the electrophysiological properties of coupling strength of gap junction and current density of smooth muscle cells are different among arterioles in the guinea pig.
Animals ; Arterioles ; cytology ; physiology ; Cerebellum ; blood supply ; Cochlea ; blood supply ; Electrophysiological Phenomena ; Female ; Guinea Pigs ; Male ; Mesenteric Arteries ; cytology ; Muscle, Smooth, Vascular ; cytology ; physiology

To evaluate the usefulness of MR cisternography fourteen patients that had hemifacial spasm and 20 control patients underwent MR cisternography. All the patients with hemifacial spasm had a confirmed vascular compression after surgery. MR cisternography was performed using a 1.5-tesla superconducting MR magnet in which a 3D (dimensional) heavily T2-weighted turbo spin-echo sequence was used. In 34 randomly selected individuals, we retrospectively determined whether MR cisternography images could be used to evaluat symptoms, and what the benefits of obtaining this image was. The results were correlated with the surgical findings. The sensitivity was 100% and the specificity was 94% in all patients having a hemifacial spasm. The offending vessels were the anterior inferior cerebellar artery (AICA) in six patients cases, the posterior inferior cerebellar artery (PICA) in six, both the vertebral artery and PICA in one, and the vertebral artery in one. All the images showed good resolution and contrast, and also showed the exact correlation between the facial nerve and intracranial vessels in the multiplaner image. The findings of neurovascular compression were well correlated with the surgical findings. We believe that high-resolution 3D MR cisternography is a very useful method for evaluating the neurovascular compression in patients that have hemifacial spasm.
Adult ; Aged ; Cerebellum/blood supply ; Cisterna Magna/radiography ; Echo-Planar Imaging ; Female ; Hemifacial Spasm/*radiography ; Human ; Magnetic Resonance Angiography ; Male ; Middle Age ; Tomography, X-Ray Computed

OBJECTIVETo study an effective method for vertebral artery-posterior inferior cerebellar artery (VA-PICA) dissecting aneurysms.

METHODSFive patients with VA-PICA dissecting aneurysms were treated surgically between December 2007 and February 2010, who were all males, aged from 40 to 55 years. Four of them presented with subarachnoid hemorrhage (SAH), 1 of them suffered from an intermittent headache on occipital area about 4 months. All the aneurysms were trapped via a far-lateral approach after revascularization of the PICAs by occipital artery-posterior inferior cerebellar artery (OA-PICA) bypass.

RESULTSAmong the 5 patients, 1 of them got a good outcome without any neurological deficit after surgery, 3 of them had postoperative lower cranial nerve palsy, 1 of them complicated with bleeding in the operative field after postoperative antithrombotic treatment, and suffered from contralateral hemiplegia after second surgery of removing hematoma. Postoperative cerebral angiographies (received by 2 patients) and CT angiographies (received by 3 patients) all showed patent bypasses and no filling of the aneurysms. During the follow-up from 2 to 29 months, 4 patients got good outcomes, 1 patient still suffered from moderate hemiplegia.

CONCLUSIONSTrapping the aneurysms after revascularization of PICA by OA-PICA bypass should be an effective method to treat the VA-PICA dissecting aneurysms, but individualized strategies also need to be considered based on different cases.

Adult ; Cerebellum ; blood supply ; Follow-Up Studies ; Humans ; Intracranial Aneurysm ; surgery ; Male ; Middle Aged ; Prognosis ; Retrospective Studies ; Treatment Outcome ; Vertebral Artery

OBJECTIVETo study the microsurgical anatomy of the posterior inferior cerebellar artery (PICA) for neurosurgery.

METHODSTwenty Chinese adult brain samples (40 sides) were measured with microscope for the diameters, lengths, origins, courses, and the branches of the PICA. The relationship between the PICA and cranial nerves was also checked.

RESULTSThere were 35 PICAs in 20 brain samples. The mean diameter of the PICAs was (1.6 +/- 0.6) mm, the mean length from PICAs' origin of vertebral artery to the vertebrobasilar junction was (16 +/- 5) mm. In 35 PICAs, 28 PICAs go through the rootlets of XII cranial nerves, 7 PICAs go through inferior XII cranial nerves, and 32 PICAs go through the rootlets of XI cranial nerves.

CONCLUSIONSPICA is an important branch artery with more variation and complex relationship to the cranial nerves trend in the vertebral artery system. It is necessary to master the microsurgical anatomy of PICA and to be careful protection during the neurosurgical operations.

Adult ; Carotid Artery, Common ; anatomy & histology ; Cerebellum ; blood supply ; Cerebral Arteries ; anatomy & histology ; Cranial Nerves ; anatomy & histology ; Humans ; Vertebral Artery ; anatomy & histology

OBJECTIVE: The purpose of this retrospective study was to report the outcome of the endovascular treatment of eight patients with eight saccular posterior inferior cerebellar artery (PICA) aneurysms. MATERIALS AND METHODS: Over the last seven years (1999-2006), eight consecutive patients with saccular PICA aneurysms were treated by endovascular methods. Five of the aneurysms were presented with subarachnoid hemorrhaging, whereas three were discovered incidentally. Four of the aneurysms (3 ruptured and 1 incidental) were treated by intrasaccular coiling, whereas the remaining four (1 ruptured and 3 incidental) were treated by vertebral artery (VA) occlusion. RESULTS: Of the four aneurysms treated by intrasaccular coiling, three were completely packed with coils and one was partially packed. In three of four patients who underwent vertebral artery occlusions, follow-up digital subtraction angiographies demonstrated thrombosed aneurysms and PICA. No procedure-related morbidity occurred and no re-bleed was encountered during a follow-up examination (mean; 31 months). CONCLUSION: As a result of this study, we found that the endovascular management of saccular PICA aneurysms should be considered as safe and effective.
Adult ; Aged ; Aneurysm, Ruptured/radiography/*therapy ; Cerebellum/blood supply/*radiography ; Cerebral Angiography ; Embolization, Therapeutic/*methods ; Female ; Humans ; Incidental Findings ; Intracranial Aneurysm/radiography/*therapy ; Male ; Middle Aged ; Retrospective Studies ; Subarachnoid Hemorrhage/radiography/*therapy ; Treatment Outcome

We report the first Korean patient with familial hemiplegic migraine type 1, with clinical and multimodal imaging findings. A 43-yr-old man was admitted for right hemianopia and aphasia, followed by coma. MRI showed only cerebellar atrophy. CT angiography showed mild vasodilation of intracranial blood vessels and increased vascularity in the left hemisphere and perfusion-weighted imaging showed elevated cerebral blood flow. Gene analysis of the patient and his mother led to the identification of a heterozygous point mutation (1997C-->T, T666M) in exon 16 of the CACNA1A gene. Familial hemiplegic migraine should be considered in patients with episodic neurological dysfunction with cerebellar atrophy.
Asian Continental Ancestry Group/*genetics ; Atrophy/genetics/metabolism ; Calcium Channels/*genetics ; Cerebellum/blood supply/*pathology ; Cerebral Angiography ; Coma/*diagnosis ; Exons ; Heterozygote ; Humans ; Magnetic Resonance Imaging ; Male ; Migraine with Aura/*diagnosis/genetics ; Point Mutation ; Republic of Korea ; Tomography, X-Ray Computed

The aim of the present study was to investigate the effects of acute hypoxia on the electrophysiological properties of vascular smooth muscle cells (VSMCs) in arteriole. Guinea-pig anterior inferior cerebellar artery (AICA) segments were isolated, and outer layer connective tissue was removed by collagenase A digestion and microforceps. By perfusion with physical saline solution containing no glucose and low oxygen, VSMC model of acute hypoxia was established. The model was studied by whole-cell patch clamp recording technique. Results were shown as below: (1) Acute hypoxia induced an outward current with amplitude of (36.4 ± 9.2) pA at holding potential of -40 mV, and the rest potential (RP) of the VSMCs was hyperpolarized from (-33.2 ± 1.9) mV to (-38.4 ± 1.5) mV. Acute hypoxia increased the outward current of VSMCs in a voltage-dependent manner, this enhancing effect being more pronounced at potentials ranging from 0 to +40 mV. The whole-cell membrane current of VSMCs induced by step command (+40 mV) increased from (650 ± 113) pA to (1 900 ± 197) pA. In the presence of 1 mmol/L tetraethylammonium (TEA), the enhancement of the VSMC membrane current by acute hypoxia was significantly reduced. (2) Acute hypoxia increased the membrane resistance (R(input)) of the VSMCs in AICA from (234 ± 63) MΩ to (1 211 ± 201) MΩ, and decreased the membrane capacitance (C(input)) from (279.3 ± 83.2) pF to (25.4 ± 1.9) pF. In the presence of 30 μmol/L 18β-glycyrrhetinic acid (18βGA) and 10 mmol/L TEA, the effects of acute hypoxia on the membrane current of VSMCs were nearly abolished. These results suggest that acute hypoxia causes vascular hyperpolarization and vasodilation, possibly by activating big conductance Ca(2+)-activated K(+) channels (BK(Ca)) of the VSMCs, and inhibits gap junctions between VSMCs, thus improving microcirculation and localizing the hypoxia-induced damage.
Animals ; Arteries ; physiopathology ; Cerebellum ; blood supply ; Female ; Gap Junctions ; metabolism ; physiology ; Guinea Pigs ; Hypoxia ; physiopathology ; In Vitro Techniques ; Male ; Muscle, Smooth, Vascular ; cytology ; metabolism ; physiology ; Myocytes, Smooth Muscle ; metabolism ; physiology ; Patch-Clamp Techniques ; Potassium Channels ; physiology

The delivery of transgenes to the central nervous system (CNS) can be a valuable tool to treat CNS diseases. Various systems for the delivery to the CNS have been developed; vascular delivery of viral vectors being most recent. Here, we investigated gene transfer to the CNS by intravenous injection of recombinant adenoviral vectors, containing green fluorescence protein (GFP) as a reporter gene. Expression of GFP was first observed 6 days after the gene transfer, peaked at 14 days, and almost diminished after 28 days. The observed expression of GFP in the CNS was highly localized to hippocampal CA regions of cerebral neocortex, inferior colliculus of midbrain, and granular cell and Purkinje cell layers of cerebellum. It is concluded that intravenous delivery of adenoviral vectors can be used for gene delivery to the CNS, and hence the technique could be beneficial to gene therapy.
Adenoviruses, Human/isolation & purification* ; Animals ; Blood-Brain Barrier ; Brain/virology* ; Cerebellum/cytology ; Cerebellum/virology ; Comparative Study ; Female ; Genes, Reporter ; Genetic Vectors/administration & dosage ; Genetic Vectors/isolation & purification ; Genetic Vectors/pharmacokinetics* ; Hippocampus/virology ; Inferior Colliculus/virology ; Injections, Intravenous ; Luminescent Proteins/analysis ; Luminescent Proteins/biosynthesis ; Luminescent Proteins/genetics ; Mice ; Mice, Inbred BALB C ; Neuroglia/virology ; Neurons/virology* ; Purkinje Cells/virology ; Pyramidal Cells/virology ; Recombinant Fusion Proteins/analysis ; Recombinant Fusion Proteins/biosynthesis ; Recombinant Fusion Proteins/genetics ; Tail/blood supply ; Tissue Distribution

The aim of the present study was to investigate the effect of 18β-glycyrrhetinic acid (18βGA) on the membrane current of vascular smooth muscle cells (VSMCs) in arteriole. Guinea pig anterior inferior cerebellar artery (AICA) and mesenteric artery (MA) were isolated, and single VSMCs were harvested using digestion with papain and collagenase IA. Outward currents of the VSMCs were recorded by whole-cell patch clamp technique. Results were shown as below: (1) 1 mmol/L 4-AP and 1 mmol/L TEA both could partially inhibit the whole-cell current of VSMCs in arterioles. (2) 18βGA inhibited the outward current of VSMCs in a concentration-dependent manner. The inhibitory rates of 10, 30 and 100 μmol/L 18βGA on the membrane current of VSMCs (+40 mV) were (25.3 ± 7.1)%, (43.1 ± 10.4)% and (68.4 ± 3.9)% respectively in AICA, and (13.2 ± 5.6)%, (34.2 ± 4.0)% and (59.3 ± 7.3)% respectively in MA. There was no significant difference between the inhibitory effects of 18βGA on AICA and MA. 18βGA also inhibited the outward current of VSMCs in a voltage-dependent manner. 18βGA induced a more pronounced inhibition of the outward current from 0 to +40 mV, especially at +40 mV. (3) With the pretreatment of 10 mmol/L TEA, the inhibitory effect of 18βGA on the membrane current of VSMCs was significantly abolished. These results suggest that the outward current of VSMCs in arterioles is mediated by voltage-dependent K(+) channels (K(v)) and big conductance calcium-activated K(+) channels (BK(Ca)), which can be inhibited by 18βGA in concentration- and voltage-dependent way.
Animals ; Arterioles ; physiology ; Cerebellum ; blood supply ; Female ; Gap Junctions ; physiology ; Glycyrrhetinic Acid ; analogs & derivatives ; pharmacology ; Guinea Pigs ; In Vitro Techniques ; Male ; Membrane Potentials ; drug effects ; Mesenteric Arteries ; cytology ; physiology ; Muscle, Smooth, Vascular ; cytology ; physiology ; Myocytes, Smooth Muscle ; physiology ; Patch-Clamp Techniques ; Potassium Channels, Calcium-Activated ; physiology ; Potassium Channels, Voltage-Gated ; physiology