1
|
Ding N, Jiang J, Tian H, Wang S, Li Z. Benign Regulation of the Astrocytic Phospholipase A 2-Arachidonic Acid Pathway: The Underlying Mechanism of the Beneficial Effects of Manual Acupuncture on CBF. Front Neurosci 2020; 13:1354. [PMID: 32174802 PMCID: PMC7054756 DOI: 10.3389/fnins.2019.01354] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 12/02/2019] [Indexed: 12/19/2022] Open
Abstract
Background The astrocytic phospholipase A2 (PLA2)-arachidonic acid (AA) pathway is crucial in understanding the reduction of cerebral blood flow (CBF) prior to cognitive deterioration. In complementary and alternative medicine, manual acupuncture (MA) is used as one of the most important therapies for Alzheimer’s disease (AD). The beneficial effects of MA on CBF were reported in our previous study. However, the underlying molecular mechanism remains largely elusive. Objective To investigate the effect of MA on the astrocytic PLA2-AA pathway in SAMP8 mice hippocampi. Methods SAMP8 mice were divided into the SAMP8 control (Pc) group, the SAMP8 MA (Pm) group and the SAMP8 donepezil (Pd) group. SAMR1 mice were used as the SAMRl control (Rc) group. Mice in the Pd group were treated with donepezil hydrochloride at 0.65 μg/g. In the Pm group, MA was applied at Baihui (GV20) and Yintang (GV29) for 20 min. The above treatments were administered once a day for 26 consecutive days. The Morris water maze was applied to assess spatial learning and memory. Immunofluorescence staining, western blot and liquid chromatography-tandem mass spectrometry were used to investigate the expression of related proteins and measure the contents of the metabolic intermediates of the PLA2-AA pathway. Results Compared with that in the Rc group, the escape latency in the Pc group significantly increased (p < 0.01); whereas, the platform crossover number and percentage of time and swimming distance in the platform quadrant decreased (p < 0.01). The hippocampal expression of PLA2, cyclooxygenase-1, cytochrome P450 proteins 2C23 and the levels of AA, prostaglandin E2 and epoxyeicosatrienoic acids of the Pc group was drastically higher than that in the Rc group (p < 0.01). These changes were reversed by MA and donepezil (p < 0.01 or p < 0.05). Conclusion MA can effectively improve the learning and memory abilities of SAMP8 mice and has a negative regulatory effect on the PLA2-AA pathway. We propose that the increase of the arterial tone, which is induced by the inhibition of vasodilatory pathway, may be a reason for the beneficial effect of MA on CBF.
Collapse
Affiliation(s)
- Ning Ding
- Department of Acupuncture, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jing Jiang
- School of Nursing, Beijing University of Chinese Medicine, Beijing, China
| | - Huiling Tian
- School of Acupuncture, Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Shun Wang
- School of Acupuncture, Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Zhigang Li
- School of Acupuncture, Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| |
Collapse
|
2
|
NMDA attenuates the neurovascular response to hypercapnia in the neonatal cerebral cortex. Sci Rep 2019; 9:18900. [PMID: 31827200 PMCID: PMC6906464 DOI: 10.1038/s41598-019-55468-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 11/29/2019] [Indexed: 11/12/2022] Open
Abstract
Cortical spreading depolarization (SD) involves activation of NMDA receptors and elicit neurovascular unit dysfunction. NMDA cannot trigger SD in newborns, thus its effect on neurovascular function is not confounded by other aspects of SD. The present study investigated if NMDA affected hypercapnia-induced microvascular and electrophysiological responses in the cerebral cortex of newborn pigs. Anesthetized piglets were fitted with cranial windows over the parietal cortex to study hemodynamic and electrophysiological responses to graded hypercapnia before/after topically applied NMDA assessed with laser-speckle contrast imaging and recording of local field potentials (LFP)/neuronal firing, respectively. NMDA increased cortical blood flow (CoBF), suppressed LFP power in most frequency bands but evoked a 2.5 Hz δ oscillation. The CoBF response to hypercapnia was abolished after NMDA and the hypercapnia-induced biphasic changes in δ and θ LFP power were also altered. MK-801 prevented NMDA-induced increases in CoBF and the attenuation of microvascular reactivity to hypercapnia. The neuronal nitric oxide synthase (nNOS) inhibitor (N-(4 S)-4-amino-5-[aminoethyl]aminopentyl-N′-nitroguanidin) also significantly preserved the CoBF response to hypercapnia after NMDA, although it didn’t reduce NMDA-induced increases in CoBF. In conclusion, excess activation of NMDA receptors alone can elicit SD-like neurovascular unit dysfunction involving nNOS activity.
Collapse
|
3
|
Bálint AR, Puskás T, Menyhárt Á, Kozák G, Szenti I, Kónya Z, Marek T, Bari F, Farkas E. Aging Impairs Cerebrovascular Reactivity at Preserved Resting Cerebral Arteriolar Tone and Vascular Density in the Laboratory Rat. Front Aging Neurosci 2019; 11:301. [PMID: 31780917 PMCID: PMC6856663 DOI: 10.3389/fnagi.2019.00301] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 10/21/2019] [Indexed: 12/26/2022] Open
Abstract
The age-related (mal)adaptive modifications of the cerebral microvascular system have been implicated in cognitive impairment and worse outcomes after ischemic stroke. The magnitude of the hyperemic response to spreading depolarization (SD), a recognized principle of ischemic lesion development has also been found to be reduced by aging. Here, we set out to investigate whether the SD-coupled reactivity of the pial arterioles is subject to aging, and whether concomitant vascular rarefaction may contribute to the age-related insufficiency of the cerebral blood flow (CBF) response. CBF was assessed with laser-speckle contrast analysis (LASCA), and the tone adjustment of pial arterioles was followed with intrinsic optical signal (IOS) imaging at green light illumination through a closed cranial window created over the parietal cortex of isoflurane-anesthetized young (2 months old) and old (18 months old) male Sprague-Dawley rats. Global forebrain ischemia and later reperfusion were induced by the bilateral occlusion and later release of both common carotid arteries. SDs were elicited repeatedly with topical 1M KCl. Pial vascular density was measured in green IOS images of the brain surface, while the density and resting diameter of the cortical penetrating vasculature was estimated with micro-computed tomography of paraformaldehyde-fixed cortical samples. Whilst pial arteriolar dilation in response to SD or ischemia induction were found reduced in the old rat brain, the density and resting diameter of pial cortical vessels, and the degree of SD-related oligemia emerged as variables unaffected by age in our experiments. Spatial flow distribution analysis identified an age-related shift to a greater representation of higher flow ranges in the reperfused cortex. According to our data, impairment of functional arteriolar dilation, at preserved vascular density and resting vascular tone, may be implicated in the age-related deficit of the CBF response to SD, and possibly in the reduced efficacy of neurovascular coupling in the aging brain. SD has been recognized as a potent pathophysiological contributor to ischemic lesion expansion, in part because of the insufficiency of the associated CBF response. Therefore, the age-related impairment of cerebral vasoreactivity as shown here is suggested to contribute to the age-related acceleration of ischemic lesion development.
Collapse
Affiliation(s)
- Armand R. Bálint
- Department of Medical Physics and Informatics, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Tamás Puskás
- Department of Medical Physics and Informatics, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Ákos Menyhárt
- Department of Medical Physics and Informatics, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Gábor Kozák
- Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Imre Szenti
- Department of Applied and Environmental Chemistry, Interdisciplinary Excellence Centre, University of Szeged, Szeged, Hungary
| | - Zoltán Kónya
- Department of Applied and Environmental Chemistry, Interdisciplinary Excellence Centre, University of Szeged, Szeged, Hungary
- MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group, University of Szeged, Szeged, Hungary
| | - Tamás Marek
- Department of Medical Physics and Informatics, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Ferenc Bari
- Department of Medical Physics and Informatics, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Eszter Farkas
- Department of Medical Physics and Informatics, Faculty of Medicine, University of Szeged, Szeged, Hungary
| |
Collapse
|
4
|
Menyhárt Á, Zölei-Szénási D, Puskás T, Makra P, Bari F, Farkas E. Age or ischemia uncouples the blood flow response, tissue acidosis, and direct current potential signature of spreading depolarization in the rat brain. Am J Physiol Heart Circ Physiol 2017; 313:H328-H337. [DOI: 10.1152/ajpheart.00222.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 05/24/2017] [Accepted: 06/07/2017] [Indexed: 12/14/2022]
Abstract
Spreading depolarization (SD) events contribute to lesion maturation in the acutely injured human brain. Neurodegeneration related to SD is thought to be caused by the insufficiency of the cerebral blood flow (CBF) response; yet the mediators of the CBF response, or their deficiency in the aged or ischemic cerebral cortex, remain the target of intensive research. Here, we postulated that tissue pH effectively modulates the magnitude of hyperemia in response to SD, the coupling of which is prone to be dysfunctional in the aged or ischemic cerebral cortex. To test this hypothesis, we conducted systematic correlation analysis between the direct current (DC) potential signature of SD, SD-associated tissue acidosis, and hyperemic element of the CBF response in the isoflurane-anesthetized, young or old, and intact or ischemic rat cerebral cortex. The data demonstrate that the amplitude of the SD-related DC potential shift, tissue acidosis, and hyperemia are tightly coupled in the young intact cortex; ischemia and old age uncouples the amplitude of hyperemia from the amplitude of the DC potential shift and acidosis; the duration of the DC potential shift, hyperemia and acidosis positively correlate under ischemia alone; and old age disproportionally elongates the duration of acidosis with respect to the DC potential shift and hyperemia under ischemia. The coincidence of the variables supports the view that local CBF regulation with SD must have an effective metabolic component, which becomes dysfunctional with age or under ischemia. Finally, the known age-related acceleration of ischemic neurodegeneration may be promoted by exaggerated tissue acidosis. NEW & NOTEWORTHY The hyperemic element of the cerebral blood flow response to spreading depolarization is effectively modulated by tissue pH in the young intact rat cerebral cortex. This coupling becomes dysfunctional with age or under ischemia, and tissue acidosis lasts disproportionally longer in the aged cortex, making the tissue increasingly more vulnerable.
Collapse
Affiliation(s)
- Ákos Menyhárt
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Dániel Zölei-Szénási
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Tamás Puskás
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Péter Makra
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Ferenc Bari
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Eszter Farkas
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| |
Collapse
|
5
|
Humeau-Heurtier A, Abraham P, Henni S. Bi-dimensional variational mode decomposition of laser speckle contrast imaging data: A clinical approach to critical limb ischemia? Comput Biol Med 2017; 86:107-112. [DOI: 10.1016/j.compbiomed.2017.05.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 05/11/2017] [Accepted: 05/11/2017] [Indexed: 10/19/2022]
|
6
|
Mikkelsen MLG, Ambrus R, Rasmussen R, Miles JE, Poulsen HH, Moltke FB, Eriksen T. The effect of dexmedetomidine on cerebral perfusion and oxygenation in healthy piglets with normal and lowered blood pressure anaesthetized with propofol-remifentanil total intravenous anaesthesia. Acta Vet Scand 2017; 59:27. [PMID: 28468670 PMCID: PMC5415812 DOI: 10.1186/s13028-017-0293-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 04/21/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND During anaesthesia and surgery, in particular neurosurgery, preservation of cerebral perfusion and oxygenation (CPO) is essential for normal postoperative brain function. The isolated effects on CPO of either individual anaesthetic drugs or entire anaesthetic protocols are of importance in both clinical and research settings. Total intravenous anaesthesia (TIVA) with propofol and remifentanil is widely used in human neuroanaesthesia. In addition, dexmedetomidine is receiving increasing attention as an anaesthetic adjuvant in neurosurgical, intensive care, and paediatric patients. Despite the extensive use of pigs as animal models in neuroscience and the increasing use of both propofol-remifentanil and dexmedetomidine, very little is known about their combined effect on CPO in pigs with uninjured brains. This study investigates the effect of dexmedetomidine on CPO in piglets with normal and lowered blood pressure during background anaesthesia with propofol-remifentanil TIVA. Sixteen healthy female Danish pigs (crossbreeds of Danish Landrace, Yorkshire and Duroc, 25-34 kg) were used. Three animals were subsequently excluded. The animals were randomly allocated into one of two groups with either normal blood pressure (NBP, n = 6) or with induced low blood pressure (LBP, n = 7). Both groups were subjected to the same experimental protocol. Intravenous propofol induction was performed without premedication. Anaesthesia was maintained with propofol-remifentanil TIVA, and later supplemented with continuous infusion of dexmedetomidine. Assessments of cerebral perfusion obtained by laser speckle contrast imaging (LSCI) were related to cerebral oxygenation measures (PbrO2) obtained by an intracerebral Clark-type Licox probe. RESULTS Addition of dexmedetomidine resulted in a 32% reduction in median PbrO2 values for the LBP group (P = 0.03), but no significant changes in PbrO2 were observed for the NBP group. No significant changes in LSCI readings were observed in either group between any time points, despite a 28% decrease in the LBP group following dexmedetomidine administration. Caval block resulted in a significant (P = 0.02) reduction in median MAP from 68 mmHg (range 63-85) at PCB to 58 mmHg (range 53-63) in the LBP group, but no significant differences in either PbrO2 or LSCI were observed due to this intervention (P = 0.6 and P = 0.3 respectively). CONCLUSIONS Addition of dexmedetomidine to propofol-remifentanil TIVA resulted in a significant decrease in cerebral oxygenation (PbrO2) measurements in piglets with lowered blood pressure. Cerebral perfusion (LSCI) did not decrease significantly in this group. In piglets with normal blood pressure, no significant changes in cerebral perfusion or oxygenation were seen in response to addition of dexmedetomidine to the background anaesthesia.
Collapse
Affiliation(s)
- Mai Louise Grandsgaard Mikkelsen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 16 Dyrlægevej, 1870 Frederiksberg C, Denmark
| | - Rikard Ambrus
- Department of Surgical Gastroenterology C, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, 9 Blegdamsvej, 2100 Copenhagen Ø, Denmark
| | - Rune Rasmussen
- Department of Neurosurgery, The Neuroscience Centre, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, 9 Blegdamsvej, 2100 Copenhagen Ø, Denmark
| | - James Edward Miles
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 16 Dyrlægevej, 1870 Frederiksberg C, Denmark
| | - Helle Harding Poulsen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 16 Dyrlægevej, 1870 Frederiksberg C, Denmark
| | - Finn Borgbjerg Moltke
- Department of Neuroanaesthesia, Rigshospitalet, University of Copenhagen, 9 Blegdamsvej, 2100 Copenhagen Ø, Denmark
- Department of Anaesthesia, Bispebjerg and Frederiksberg Hospitals, Faculty of Health and Medical Sciences, University of Copenhagen, 23 Bispebjerg Bakke, 2400 Copenhagen NV, Denmark
| | - Thomas Eriksen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 16 Dyrlægevej, 1870 Frederiksberg C, Denmark
| |
Collapse
|
7
|
Menyhárt Á, Zölei-Szénási D, Puskás T, Makra P, Orsolya MT, Szepes BÉ, Tóth R, Ivánkovits-Kiss O, Obrenovitch TP, Bari F, Farkas E. Spreading depolarization remarkably exacerbates ischemia-induced tissue acidosis in the young and aged rat brain. Sci Rep 2017; 7:1154. [PMID: 28442781 PMCID: PMC5430878 DOI: 10.1038/s41598-017-01284-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 03/27/2017] [Indexed: 11/16/2022] Open
Abstract
Spreading depolarizations (SDs) occur spontaneously in the cerebral cortex of subarachnoid hemorrhage, stroke or traumatic brain injury patients. Accumulating evidence prove that SDs exacerbate focal ischemic injury by converting zones of the viable but non-functional ischemic penumbra to the core region beyond rescue. Yet the SD-related mechanisms to mediate neurodegeneration remain poorly understood. Here we show in the cerebral cortex of isoflurane-anesthetized, young and old laboratory rats, that SDs propagating under ischemic penumbra-like conditions decrease intra and- extracellular tissue pH transiently to levels, which have been recognized to cause tissue damage. Further, tissue pH after the passage of each spontaneous SD event remains acidic for over 10 minutes. Finally, the recovery from SD-related tissue acidosis is hampered further by age. We propose that accumulating acid load is an effective mechanism for SD to cause delayed cell death in the ischemic nervous tissue, particularly in the aged brain.
Collapse
Affiliation(s)
- Ákos Menyhárt
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary
| | - Dániel Zölei-Szénási
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary
| | - Tamás Puskás
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary
| | - Péter Makra
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary
| | - M Tóth Orsolya
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary
| | - Borbála É Szepes
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary
| | - Réka Tóth
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary
| | - Orsolya Ivánkovits-Kiss
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary
| | - Tihomir P Obrenovitch
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary
| | - Ferenc Bari
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary
| | - Eszter Farkas
- Department of Medical Physics and Informatics, Faculty of Medicine & Faculty of Science and Informatics, University of Szeged, H-6720 Szeged, Korányi fasor 9, Hungary.
| |
Collapse
|
8
|
Estato V, Nascimento A, Antunes B, Gomes F, Coelho L, Rangel R, Garzoni L, Daliry A, Bousquet P, Tibiriçá E. Cerebral Microvascular Dysfunction and Inflammation Are Improved by Centrally Acting Antihypertensive Drugs in Metabolic Syndrome. Metab Syndr Relat Disord 2016; 15:26-35. [PMID: 27929741 DOI: 10.1089/met.2016.0085] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND We aimed to investigate the effects of chronic oral treatment with centrally acting antihypertensive drugs, such as clonidine (CLO), an α2-adrenoceptor agonist, or LNP599, a selective I1 imidazoline receptor agonist, on brain microvascular function in rats with high-fat diet (HFD)-induced metabolic syndrome. METHODS Male Wistar Kyoto rats were maintained on a normal diet (CON) or a HFD for 20 weeks. After this period, the HFD group received oral CLO (0.1 mg/kg), LNP599 (20 mg/kg), or vehicle daily for 4 weeks. Systolic blood pressure and heart rate (HR) were evaluated by photoplethysmography. Functional capillary density, endothelial function, and endothelial-leukocyte interactions in the brain were investigated by intravital video microscopy. Cerebral microcirculatory flow was evaluated by laser speckle contrast imaging. Brain tissue endothelial nitric oxide synthase, oxidative enzyme, and inflammatory marker expression levels were analyzed. RESULTS Metabolic syndrome decreased brain functional capillary density and microvascular blood perfusion, changes accompanied by deficient brain microcirculation vasodilatory responses to acetylcholine. Significant numbers of rolling and adherent leukocytes were also observed in the brain venules. Chronic sympathetic inhibition with clonidine and LNP599 reduced blood pressure and HR. These effects were accompanied by reversals of cerebral capillary rarefaction, improvements in cerebral microvascular blood flow and endothelial function, and decreases in endothelial-leukocyte interactions in the cerebral venules. CONCLUSIONS Our results suggest that central sympathetic inhibition exerts beneficial effects by increasing perfusion and reducing inflammatory marker expression and oxidative stress in the brains of rats with metabolic syndrome. Centrally acting antihypertensive drugs may be helpful in regulating cerebral microcirculatory function and vascular inflammation in metabolic syndrome.
Collapse
Affiliation(s)
- Vanessa Estato
- 1 Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation , Rio de Janeiro, Brazil .,2 Institute of Drug Technology , Owaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Alessandro Nascimento
- 1 Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation , Rio de Janeiro, Brazil
| | - Barbara Antunes
- 1 Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation , Rio de Janeiro, Brazil
| | - Fabiana Gomes
- 1 Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation , Rio de Janeiro, Brazil
| | - Laura Coelho
- 3 Laboratory for Innovations in Therapies, Education and Bioproducts, Oswaldo Cruz Foundation , Rio de Janeiro, Brazil
| | - Raquel Rangel
- 1 Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation , Rio de Janeiro, Brazil
| | - Luciana Garzoni
- 1 Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation , Rio de Janeiro, Brazil .,3 Laboratory for Innovations in Therapies, Education and Bioproducts, Oswaldo Cruz Foundation , Rio de Janeiro, Brazil
| | - Anissa Daliry
- 1 Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation , Rio de Janeiro, Brazil
| | - Pascal Bousquet
- 4 Laboratory of Neurobiology and Cardiovascular Pharmacology, Faculty of Medicine, University of Strasbourg , Strasbourg, France
| | - Eduardo Tibiriçá
- 1 Laboratory of Cardiovascular Investigation, Oswaldo Cruz Foundation , Rio de Janeiro, Brazil .,5 National Institute of Cardiology , Rio de Janeiro, Brazil
| |
Collapse
|
9
|
Ideguchi M, Kajiwara K, Yoshikawa K, Goto H, Sugimoto K, Inoue T, Nomura S, Suzuki M. Avoidance of ischemic complications after resection of a brain lesion based on intraoperative real-time recognition of the vasculature using laser speckle flow imaging. J Neurosurg 2016; 126:274-280. [PMID: 27035176 DOI: 10.3171/2016.1.jns152067] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To avoid ischemic complications, it is important to consider the arteries in resection planning for lesions such as a vascular intraparenchymal tumor and arteriovenous malformation. Here, the clinical application of laser speckle flow imaging (LSFI) as a complementary method for the management of mass lesion-related arteries during surgery was evaluated. METHODS LSFI was performed in 12 patients with mass lesion-related arteries and brain tumor or arteriovenous malformation. The portable LSFI device was centered over the surgical field, and the relative cerebral blood flow (CBF) before and after the temporary interruption of the arteries was measured through continuous recording. CBF fluctuations permitted the classification of 3 kinds of artery-a feeding artery (FA), a "passing through" artery (PA), and a combined FA and PA (FA+PA)-based on decreased relative CBF in the inner resection area and unchanged CBF in the surrounding area (FA), unchanged CBF in the inner area and decreased CBF in the surrounding area (PA), or decreased CBF in both areas (FA+PA). This information allowed the appropriate management of these arteries and avoidance of postoperative ischemic complications. RESULTS Good visualization of CBF in the surgical field and relative CBF measurements in the regions of interest were achieved in real time with excellent spatiotemporal resolution. In 11 patients (92%) and 20 regions of interest, a decline in CBF was observed after temporary interruption of the FA (n = 8), PA (n = 2), and FA+PA (n = 2) types. There was a significant average reduction in CBF of 15.3% ± 29.0%. There were no ischemic complications, and only 1 patient had a postoperative ischemic lesion caused by resection through an artery that could not be viewed by LSFI due to a positional problem. CONCLUSIONS LSFI permits noninvasive and rapid intraoperative real-time recognition of mass lesion-related vasculature. This information can be used to avoid ischemic complications as a procedure complementary to neurophysiological monitoring.
Collapse
Affiliation(s)
- Makoto Ideguchi
- Department of Neurosurgery, Yamaguchi University Graduate School of Medicine; and
| | - Koji Kajiwara
- Department of Neurosurgery, Ube-nishi Rehabilitation Hospital, Ube, Japan
| | - Koichi Yoshikawa
- Department of Neurosurgery, Yamaguchi University Graduate School of Medicine; and
| | - Hisaharu Goto
- Department of Neurosurgery, Yamaguchi University Graduate School of Medicine; and
| | - Kazutaka Sugimoto
- Department of Neurosurgery, Yamaguchi University Graduate School of Medicine; and
| | - Takao Inoue
- Department of Neurosurgery, Yamaguchi University Graduate School of Medicine; and
| | - Sadahiro Nomura
- Department of Neurosurgery, Yamaguchi University Graduate School of Medicine; and
| | - Michiyasu Suzuki
- Department of Neurosurgery, Yamaguchi University Graduate School of Medicine; and
| |
Collapse
|
10
|
Vaz PG, Humeau-Heurtier A, Figueiras E, Correia C, Cardoso J. Laser Speckle Imaging to Monitor Microvascular Blood Flow: A Review. IEEE Rev Biomed Eng 2016; 9:106-20. [DOI: 10.1109/rbme.2016.2532598] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
11
|
Kazmi SMS, Wu RK, Dunn AK. Evaluating multi-exposure speckle imaging estimates of absolute autocorrelation times. OPTICS LETTERS 2015; 40:3643-3646. [PMID: 26258378 DOI: 10.1364/ol.40.003643] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Multi-exposure speckle imaging (MESI) is a camera-based flow-imaging technique for quantitative blood-flow monitoring by mapping the speckle-contrast dependence on camera exposure duration. The ability of laser speckle contrast imaging to measure the temporal dynamics of backscattered and interfering coherent fields, in terms of the accuracy of autocorrelation measurements, is a major unresolved issue in quantitative speckle flowmetry. MESI fits for a number of parameters including an estimate of the electric field autocorrelation decay time from the imaged speckles. We compare the MESI-determined correlation times in vitro and in vivo with accepted true values from direct temporal measurements acquired with a photon-counting photon-multiplier tube and an autocorrelator board. The correlation times estimated by MESI in vivo remain on average within 14±11% of those obtained from direct temporal autocorrelation measurements, demonstrating that MESI yields highly comparable statistics of the time-varying fields that can be useful for applications seeking not only quantitative blood flow dynamics but also absolute perfusion.
Collapse
|
12
|
Kazmi SMS, Faraji E, Davis MA, Huang YY, Zhang XJ, Dunn AK. Flux or speed? Examining speckle contrast imaging of vascular flows. BIOMEDICAL OPTICS EXPRESS 2015. [PMID: 26203384 PMCID: PMC4505712 DOI: 10.1364/boe.6.002588] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Speckle contrast imaging enables rapid mapping of relative blood flow distributions using camera detection of back-scattered laser light. However, speckle derived flow measures deviate from direct measurements of erythrocyte speeds by 47 ± 15% (n = 13 mice) in vessels of various calibers. Alternatively, deviations with estimates of volumetric flux are on average 91 ± 43%. We highlight and attempt to alleviate this discrepancy by accounting for the effects of multiple dynamic scattering with speckle imaging of microfluidic channels of varying sizes and then with red blood cell (RBC) tracking correlated speckle imaging of vascular flows in the cerebral cortex. By revisiting the governing dynamic light scattering models, we test the ability to predict the degree of multiple dynamic scattering across vessels in order to correct for the observed discrepancies between relative RBC speeds and multi-exposure speckle imaging estimates of inverse correlation times. The analysis reveals that traditional speckle contrast imagery of vascular flows is neither a measure of volumetric flux nor particle speed, but rather the product of speed and vessel diameter. The corrected speckle estimates of the relative RBC speeds have an average 10 ± 3% deviation in vivo with those obtained from RBC tracking.
Collapse
Affiliation(s)
- S. M. Shams Kazmi
- The University of Texas at Austin, Department of Biomedical Engineering, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
| | - Ehssan Faraji
- The University of Texas at Austin, Department of Biomedical Engineering, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
| | - Mitchell A. Davis
- The University of Texas at Austin, Department of Biomedical Engineering, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
| | - Yu-Yen Huang
- The University of Texas at Austin, Department of Biomedical Engineering, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
- Currently with Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, USA
| | - Xiaojing J. Zhang
- The University of Texas at Austin, Department of Biomedical Engineering, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
- Currently with Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, USA
| | - Andrew K. Dunn
- The University of Texas at Austin, Department of Biomedical Engineering, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
| |
Collapse
|
13
|
Kazmi SMS, Richards LM, Schrandt CJ, Davis MA, Dunn AK. Expanding applications, accuracy, and interpretation of laser speckle contrast imaging of cerebral blood flow. J Cereb Blood Flow Metab 2015; 35:1076-84. [PMID: 25944593 PMCID: PMC4640282 DOI: 10.1038/jcbfm.2015.84] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 02/17/2015] [Accepted: 03/09/2015] [Indexed: 12/21/2022]
Abstract
Laser speckle contrast imaging (LSCI) provides a rapid characterization of cortical flow dynamics for functional monitoring of the microcirculation. The technique stems from interactions of laser light with moving particles. These interactions encode the encountered Doppler phenomena within a random interference pattern imaged in widefield, known as laser speckle. Studies of neurovascular function and coupling with LSCI have benefited from the real-time characterization of functional dynamics in the laboratory setting through quantification of perfusion dynamics. While the technique has largely been relegated to acute small animal imaging, its scalability is being assessed and characterized for both chronic and clinical neurovascular imaging.
Collapse
Affiliation(s)
- S M Shams Kazmi
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Lisa M Richards
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Christian J Schrandt
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Mitchell A Davis
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Andrew K Dunn
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| |
Collapse
|
14
|
Humeau-Heurtier A, Mahé G, Abraham P. Microvascular blood flow monitoring with laser speckle contrast imaging using the generalized differences algorithm. Microvasc Res 2015; 98:54-61. [PMID: 25576743 DOI: 10.1016/j.mvr.2014.12.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 12/22/2014] [Accepted: 12/27/2014] [Indexed: 10/24/2022]
Abstract
Laser speckle contrast imaging (LSCI) is a full-field optical technique to monitor microvascular blood flow with high spatial and temporal resolutions. It is used in many medical fields such as dermatology, vascular medicine, or neurosciences. However, LSCI leads to a large amount of data: image sampling frequency is often of several Hz and recordings usually last several minutes. Therefore, clinicians often perform regions of interest in which a spatial averaging of blood flow is performed and the result is followed with time. Unfortunately, this leads to a poor spatial resolution for the analyzed data. At the same time, a higher spatial resolution for the perfusion maps is wanted. To get over this dilemma we propose a new post-acquisition visual representation for LSCI perfusion data using the so-called generalized differences (GD) algorithm. From a stack of perfusion images, the procedure leads to a new single image with the same spatial resolution as the original images and this new image reflects perfusion changes. The algorithm is herein applied on simulated stacks of images and on experimental LSCI perfusion data acquired in three different situations with a commercialized laser speckle contrast imager. The results show that the GD algorithm provides a new way of visualizing LSCI perfusion data.
Collapse
Affiliation(s)
- Anne Humeau-Heurtier
- University of Angers, LARIS - Laboratoire Angevin de Recherche en Ingénierie des Systèmes, 62 Avenue Notre-Dame du Lac, 49000 Angers, France.
| | - Guillaume Mahé
- University of Rennes 1, CHU of Rennes, Pôle Imagerie Médicale et Explorations Fonctionnelles, 35033 Rennes Cedex 9, France; INSERM, CIC 1414 "Ischemia, Macro and Microcirculation" Group, 35033 Rennes Cedex 9, France
| | - Pierre Abraham
- University of Angers, CHU of Angers, Laboratoire de Physiologie et d'Explorations Vasculaires, UMR CNRS 6214-INSERM 1083, 49033 Angers Cedex 01, France
| |
Collapse
|
15
|
Kazmi SMS, Balial S, Dunn AK. Optimization of camera exposure durations for multi-exposure speckle imaging of the microcirculation. BIOMEDICAL OPTICS EXPRESS 2014; 5:2157-71. [PMID: 25071956 PMCID: PMC4102356 DOI: 10.1364/boe.5.002157] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/19/2014] [Accepted: 05/30/2014] [Indexed: 05/19/2023]
Abstract
Improved Laser Speckle Contrast Imaging (LSCI) blood flow analyses that incorporate inverse models of the underlying laser-tissue interaction have been used to develop more quantitative implementations of speckle flowmetry such as Multi-Exposure Speckle Imaging (MESI). In this paper, we determine the optimal camera exposure durations required for obtaining flow information with comparable accuracy with the prevailing MESI implementation utilized in recent in vivo rodent studies. A looping leave-one-out (LOO) algorithm was used to identify exposure subsets which were analyzed for accuracy against flows obtained from analysis with the original full exposure set over 9 animals comprising n = 314 regional flow measurements. From the 15 original exposures, 6 exposures were found using the LOO process to provide comparable accuracy, defined as being no more than 10% deviant, with the original flow measurements. The optimal subset of exposures provides a basis set of camera durations for speckle flowmetry studies of the microcirculation and confers a two-fold faster acquisition rate and a 28% reduction in processing time without sacrificing accuracy. Additionally, the optimization process can be used to identify further reductions in the exposure subsets for tailoring imaging over less expansive flow distributions to enable even faster imaging.
Collapse
Affiliation(s)
- S. M. Shams Kazmi
- Department of Biomedical Engineering, The University of Texas at Austin, 107 W. Dean Keeton C0800, Austin, Texas. 78712, USA
| | - Satyajit Balial
- Department of Biomedical Engineering, The University of Texas at Austin, 107 W. Dean Keeton C0800, Austin, Texas. 78712, USA
| | - Andrew K. Dunn
- Department of Biomedical Engineering, The University of Texas at Austin, 107 W. Dean Keeton C0800, Austin, Texas. 78712, USA
| |
Collapse
|
16
|
Nomura S, Inoue T, Ishihara H, Koizumi H, Suehiro E, Oka F, Suzuki M. Reliability of laser speckle flow imaging for intraoperative monitoring of cerebral blood flow during cerebrovascular surgery: comparison with cerebral blood flow measurement by single photon emission computed tomography. World Neurosurg 2013; 82:e753-7. [PMID: 24047822 DOI: 10.1016/j.wneu.2013.09.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 08/11/2013] [Accepted: 09/07/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To determine the clinical utility of laser speckle flow imaging (LSFI) and its comparability to (123)I-iodoamphetamine single photon emission computed tomography (IMP-SPECT), we used LSFI to monitor cerebral blood flow (CBF) during extracranial-intracranial (EC-IC) bypass surgery. METHODS Intraoperative intensity of CBF (iCBF) by LSFI and preoperative and postoperative CBF by IMP-SPECT were measured in 3 patients with internal carotid artery (ICA) aneurysms who were undergoing ICA trapping surgery and in 16 patients with major cerebral artery occlusion who were undergoing EC-IC bypass surgery. RESULTS The decrease in iCBF (16.9% ± 2.3%) with ICA interruption was equivalent to the decrease in CBF during the preoperative balloon test occlusion, as measured by IMP-SPECT (12.2% ± 4.4%). Whether preserved iCBF in LSFI promised postoperative intact CBF was not determined, as no patient showed ischemic tolerance by ICA occlusion. The increase in iCBF resulting from EC-IC bypass correlated moderately with the increase in postoperative CBF as measured by IMP-SPECT. However, the increase in iCBF was too small to be recognized intraoperatively by visual inspection. CONCLUSIONS Although LSFI clearly demonstrated a decrease in CBF, the information is taken only from the surface of the brain. Combined use of LFSI with an electrophysiologic examination is required for intraoperative diagnosis of ischemia. LSFI was not sensitive enough to detect increased CBF by superficial temporal artery-to-middle cerebral artery anastomosis, because CBF changes are minimized during anesthesia, probably owing to low metabolic activity.
Collapse
Affiliation(s)
- Sadahiro Nomura
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan.
| | - Takao Inoue
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan
| | - Hideyuki Ishihara
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan
| | - Hiroyasu Koizumi
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan
| | - Eiichi Suehiro
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan
| | - Fumiaki Oka
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan
| | - Michiyasu Suzuki
- Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan
| |
Collapse
|
17
|
Gong P, Hua R, Zhang Y, Zhao H, Tang Z, Mei X, Zhang M, Cui J, Li C. Hypothermia-induced neuroprotection is associated with reduced mitochondrial membrane permeability in a swine model of cardiac arrest. J Cereb Blood Flow Metab 2013; 33:928-34. [PMID: 23486294 PMCID: PMC3677114 DOI: 10.1038/jcbfm.2013.33] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Increasing evidence has shown that mild hypothermia is neuroprotective for comatose patients resuscitated from cardiac arrest, but the mechanism of this protection is not fully understood. The aim of this study was to determine whether prolonged whole-body mild hypothermia inhibits mitochondrial membrane permeability (MMP) in the cerebral cortex after return of spontaneous circulation (ROSC). Thirty-seven inbred Chinese Wuzhishan minipigs were successfully resuscitated after 8 minutes of untreated ventricular fibrillation (VF) and underwent recovery under normothermic (NT) or prolonged whole-body mild hypothermic (HT; 33°C) conditions for 24 or 72 hours. Cerebral samples from the frontal cortex were collected at 24 and 72 hours after ROSC. Mitochondria were isolated by differential centrifugation. At 24 hours, relative to NT, HT was associated with reductions in opening of the mitochondrial permeability transition pore, release of pro-apoptotic substances from mitochondria, caspase 3 cleavage, apoptosis, and neurologic deficit scores, as well as increases in mitochondrial membrane potential and mitochondrial respiration. Together, these findings suggest that mild hypothermia inhibits ischemia-induced increases in MMP, which may provide neuroprotection against cerebral injury after cardiac arrest.
Collapse
Affiliation(s)
- Ping Gong
- Department of Emergency, First Hospital affiliated to Dalian Medical University, Dalian, China
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Kazmi SMS, Parthasarthy AB, Song NE, Jones TA, Dunn AK. Chronic imaging of cortical blood flow using Multi-Exposure Speckle Imaging. J Cereb Blood Flow Metab 2013; 33:798-808. [PMID: 23571277 PMCID: PMC3677120 DOI: 10.1038/jcbfm.2013.57] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chronic imaging of cerebral blood flow (CBF) is an important tool for investigating vascular remodeling after injury such as stroke. Although techniques such as Laser Speckle Contrast Imaging (LSCI) have emerged as valuable tools for imaging CBF in acute experiments, their utility for chronic measurements or cross-animal comparisons has been limited. Recently, an extension to LSCI called Multi-Exposure Speckle Imaging (MESI) was introduced that increases the quantitative accuracy of CBF images. In this paper, we show that estimates of chronic blood flow are better with MESI than with traditional LSCI. We evaluate the accuracy of the MESI flow estimates using red blood cell (RBC) photographic tracking as an absolute flow calibration in mice over several days. The flow measures computed using the MESI and LSCI techniques were found to be on average 10% and 24% deviant (n=9 mice), respectively, compared with RBC velocity changes. We also map CBF dynamics after photo-thrombosis of selected cortical microvasculature. Correlations of flow dynamics with RBC tracking were closer with MESI (r=0.88) than with LSCI (r=0.65) up to 2 weeks from baseline. With the increased quantitative accuracy, MESI can provide a platform for studying the efficacy of stroke therapies aimed at flow restoration.
Collapse
|