BRAIN ACTIVATION AND CBF CONTROL

These proceedings cover the basic physiology that underlies neurovascular coupling. The methodology supporting this data utilises tools for mapping brain functions such as functional MRI, PET, optical imaging, NIR's, etc. Topics include neuroimaging physiology, neurovascular mediators, cerebral microcirculation, and the relationship between these.

Preface.

Chapter 1: Opening lectures.

Microcirculation - historical background and conceptual update (P. Gaehtgens). The circulatory and metabolic correlates of functional activity (M. Raichle).

Chapter 2: Brain imaging.

Hemodynamic models and BOLD signal.

Coupling between CBF and CMRO2 during neuronal activity (R.B. Buxton). Flow-metabolism relationship during brain activation and respiratory manipulations (R. Hoge et al.). Spatial specificity of CBF and BOLD responses induced by neural activity (S.-G. Kim et al.). Activated areas found by BOLD, CBF, and changes in CMRO2 during somatosensory stimulation do not co-localize in rat cortex (W. Schwindt, M. Burke, M. Hoehn).

Linearity to neuronal activity.

Quantitative fMRI of rat brain by multi-model MRI and MRS measurements (F. Hyder et al.). Dynamic nonlinearity in BOLD contrast: neuronal or hemodynamic? (P. Bandettini et al.). Oxygen delivery to the brain during behavioral activation at acute normobaric hypoxia (I. Law et al.). Quantitative aspects of changes in cerebral blood flow induced by neuronal activation (I. Kanno, T. Matsuura, H. Ito). Evoked cerebral blood flow is linear to neuronal activation but independent of metabolic oxygen demand (T. Matsuura, I. Kanno). Cortical blood flow through individual capillaries in rat vibrissa S1 cortex: stimulus induced changes in flow are comparable to the underlying fluctuations in flow (D. Kleinfeld).

Oxygen delivery and microcirculation.

Model of oxygen delivery to brain tissue in vivo explains beneficial effect of hypothermia in ischemia (A. Gjedde et al.). Neuronal activation induced changes in microcirculatory hemoglobin oxygenation: to dip or not to dip (U. Lindauer et al.). Spatio-temporal characteristics of neurovascular coupling in the aneathetized cat and the awake monkey (I. Vanzetta, H. Slovin, A. Grinvald). Simultaneous measurements of brain tissue P O2 and cerebral blood flow during functional stimulation (B.M. Ances et al.). Contribution of blood volume changes to intrinsic optical signals (M. Fukuda). Sustained microvascular flow response to functional activation in rat cerebral cortex (I. Schiszler et al.). Quantitative optical imaging of brain activity-human and animal studies (M. Tamura et al.).

Neuronal activity induced effects.

Role of astrocytes in coupling synaptic activity to glucose utilization (L. Pellerin et al.). Role of neuronal nitric oxide in the regional neurovascular coupling. Voxel based comparison between perfusion and metabolic PET images (T. Hayashi et al.). Hemodynamic and metabolic features of cerebral activation (O.B. Paulson, I. Law). Inhibition and functional magnetic resonance imaging (P. Ritter, A. Villringer). Dynamic changes of CBF, CMRO2, OEF, CMRglc, CBV, and ADC during neuronal suppression due to hypothermia (M. Sakoh et al.). Cerebral metabolic compartmentation: the effects of hypothermia and metabolic activation (E. Nemoto et al.). Intrinsic optical recording of somatosensory response in human cerebral cortex during brain tumor surgery (T. Nariai et al.).

Chapter 3: Mediators.

Neuronal, astroglial and other mediators.

Activity-induced changes in cerebellar blood flow (M. Lauritzen, K. Caesar). Neurovascular coupling in health and disease: lessons from transgenic mice (C. Iadecola et al.). Neuronal messengers as mediators of microvascular tone in the cerebral cortex (E. Hamel et al.). The red blood cell, ATP and integrated vascular responses to neuronal stimulation (H. Dietrich, M.L. Ellsworth, R.G. Dacey). Regulation of the cerebral circulation by cytochrome P450 epoxygenase activity (X. Peng et al.). Epoxyeicosatetrinoic acids released by astrocytes: function in cerebral angiogenesis (C. Zhang, D.R. Harder). Effects of activation of glutamate receptors on neurons and blood vessels (D. Busija et al.). The metabotropic glutamate receptor system: a novel pathway for the molecular protection against microvascular programmed cell death (K. Maiese, S.-H. Lin, Z.Z. Chong).

Neural and endothelial mediators.

The Roy-Sherrington hypothesis: facts and surmises (P. S¨¢ndor et al.). Adrenergic and cholinergic modulation of cerebrovascular nitrergic vasodilation (T. Lee). Endothelium-derived hyperpolarizing factor in the cerebral circulation (R. Bryan et al.). Variations in CBF during hypotension and in cortical eNOS in rats (S.C. Jones et al.). Neuronal nitric oxide synthase in the cerebrovascular endothelium (Z. Beny¨® et al.). Mechanisms of cGMP-induced cerebral vasodilatation - contractile agonist and developmental age make a difference (W. Pearce, S.M. Nauli).

Hormonal regulation.

Impact of hormones on the regulation of cerebral vascular tone (D. Krause et al.). Unique aspects of NO-related cerebrovascular regulation: influence of estrogen and caveolin-1 (D.A. Pelligrino et al.). Effects of estrogen on the microcirculation and thrombus formation in pial vessels of the rat (Y. Sasaki et al.).

Chapter 4: Microcirculation.

Spreading depression and microcirculation.

Imaging and preventing spreading depression independent of cerebral blood flow (R.D. Andrew et al.). A time-variable concentric wave-ring increase in light transparency and associated microflow changes during a potassium-induced spreading depression in the rat cerebral cortex (M. Tomita et al.). Real-time microcirculatory changes due to spreading depression under MCA occlusion (E. Pinard et al.).

Ischemia, depolarization and microcirculation.

Functional activation of peri-infarct tissue for prediction of recovery after focal ischemia (W.-D. Heiss). Ischemic depression of neuronal activity: real time comparison between DC potential changes and alterations of ion and transmitter homeostasis (R. Graf et al.). Ischemic energy failure and ion shifts are smaller and slower in white matter than in gray matter (E. Kumura et al.). Temporal profile of gene induction after venous ischemia accompanied by spreading depression as compared to spreading depression alone (T. Kaido et al.). Ischemia caused by inverse coupling between neuronal activation and cerebral blood flow in rats (J.P. Dreier et al.).

Regulatory factors and microcirculation.

Tumor necrosis factor-¦Á, heme oxygenase-1 and manganese superoxide dismutase immunostaining of vessels and perivascular brain cells provides evidence for cyclic activation and inactivation of brain vessel segments (C.A. Ruetzler et al.). Control of flow on the microvascular level (W. Kuschinsky, J. Vogel). Response of cerebral neocapillaries to acetylcholine: an intravital microscopic observation (Y. Nageswari, T. Yamakawa, H. Niimi). Imaging synchronization and propagation of intracellular calcium oscillation during non-synaptic seizure-like neuronal activity in rat (Y. Takiyama et al.). Therapeutic efficiency of transcranial magnetic stimulation for amyotrophic lateral sclerosis and spincerebellar degeneration (M. Horiuchi et al.).

Author index.

Keyword index.