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We have measured depth profiles of extracellular pH (pHECR) and PO2 (PtO2) as well as the kinetics of changes of pHECR in the isolated brain stem-spinal cord preparation of the neonatal rat using pH and PO2 microelectrodes that entered from the ventral surface. When the preparation was superfused with control mock cerebrospinal fluid (Control mock CSF; pH =(More)
We have extracellularly recorded single neuron activity in the ventral medulla of the isolated brain stem-spinal cord preparation of the neonatal rat (37 preparations) in order to test their sensitivity to changes in CO2/H+. Search for neuronal activity was performed when the preparation was superfused with control mock CSF (equilibrated with 2% CO2, 90% O2(More)
Experimental brain tumors were produced in cats by xenotransplantation of the rat glioma clone F98 into the white matter of the left hemisphere. One to 4 weeks after implantation, local adenosine triphosphate (ATP), glucose, lactate, and tissue pH were measured via imaging techniques in cryostat sections passing through the center of the tumor and(More)
We have used the isolated brainstem-spinal cord preparation of the neonatal rat to study the effects of theophylline on the ventilatory response to hypoxia. The brainstem-spinal cord was isolated from neonatal rats (0-4 days) and superfused with mock cerebrospinal fluid (CSF), equilibrated with a gas mixture (FO2, 0.90; FCO2, 0.02; FN2, 0.08; control CSF)(More)
Multiexponential evaluation of in vivo multi-echo T2 measurements at 4.7T in cat brain with implanted tumour led to monoexponential results in all tissues. T2 of normal brain tissue, tumour and oedema was 67 ms, 10-100 ms and 90-180 ms, respectively. In the ventricles biexponential solutions were observed with T2 values and relative contributions of these(More)
Intracellular pH (pHi) and membrane potential (Em) were measured in vivo in expiratory neurones and glial cells in the medulla of anaesthetized cats using double-barrelled H(+)-sensitive microelectrodes. In glial cells, stimulation of spinal pathways evoked a depolarization of up to 12 mV amplitude and an increase of pHi (7.25 +/- 0.15) by maximally 0.1 pH(More)
The main purpose of this study was to evaluate the role of the pons in hypoxic respiratory depression (HRD) of the neonatal rat. Experiments were conducted using the isolated brainstem-spinal cord preparation of the neonatal rat (1-3 days old). The brainstem was transected at various levels. We found that ablation of the diencephalon decreased respiratory(More)
The measurement of changes in ion activity (e.g., pH) in neurons requires fine tip-sized double-barreled microelectrodes: one channel being equipped with an ion-selective liquid membrane, the other used for measurement of the membrane potential. The limited bandwidth and the differing transfer functions for electrical and ionic signals necessitate frequency(More)
Local cerebral blood flow, the permeability of the blood-brain barrier to sodium and serum albumin, and the content of electrolytes were investigated in rats before and at 4 h and 24 h following permanent occlusion of the middle cerebral artery (MCA). Measurements were carried out by triple tracer autoradiography, using 131I-iodoantipyrin, 22NaCl and(More)