Publisher:

Elsevier

Place of publishing:

Amsterdam

Type of object:

Journal/Article

Abstract:

Lowering the temperature of the brain can affect it in either a beneficial or an adverse manner. The ability of mild hypothermia to reduce brain volume has been extensively used by neurosurgeons in alleviating increased intracranial pressure and cerebral edema. On the other hand, a number of adverse effects have been reported following cooling of the brain below 28°C. At these temperatures numerous clinical complications (such as cerebral edema or hypoxic brain injury) and experimental disturbances (such as a breakdown of the blood-brain barrier) have been reported (Brendel et al., 1966). A further elucidation of the basic changes due to lowering brain temperature appears to be of considerable importance.Hypothermia causes an increase in the electric impedance of brain tissue in the rabbit (Collewijn and Schade, 1962, 1964). This increase was thought to be a result of changed physical properties of the tissue since a similar change was found in electrolyte solutions at corresponding temperatures (Collewijn and Schade, 1962).Recently a series of experiments were designed in our laboratory (Li et al., 1966) for the study of physiological changes in the brain under hypothermia. These experiments show that impedance changes recorded from the grey matter at temperatures above 20°C were in accordance with temperature coefficients of the blood serum and NaCl solution. Below this temperature, the changes were greater than those recorded from serum and electrolyte fluid. These observations probably reflect changes in the electrolyte and extracellular compartments, as has been reported to occur in asphyxia (Van Harreveld, 1957).It was then conjectured that alteration in such basic properties of nervous parenchyma should influence penetration of various substances from the cerebrospinal fluid (CSF) (Davson and Spaziani, 1962). After crossing the ependymal barrier the substances can migrate further in several ways. Generally, the inert, extracellular compounds, such as inulin, may spread primarily by passive diffusion through extracellular spaces (Rail et al., 1962), whereas, an active transport mechanism has been implicated in penetration of diverse substances such as histamine (Draskoci et a!., 1960), amino acids(Lajtha, 1962; Levin et al., 1966), and albumin (Klatzo et a!., 1964).The purpose of the present study is to correlate some of the electrophysiological data obtained after brain cooling with observations on periventricular penetration of substances, selected for their association with either diffusion or active transport.

Relation:

Progress in Brain Research

Volume:

29

Start page:

385

End page:

399

Detailed Resource Type:

Article (offprint)

Format:

pdf

Resource Identifier:

oai:rcin.org.pl:79680

Language:

eng

Rights:

Creative Commons Attribution BY 4.0 license

Terms of use:

Copyright-protected material. [CC BY 4.0] May be used within the scope specified in Creative Commons Attribution BY 4.0 license, full text available at: ; -

Digitizing institution:

Mossakowski Medical Research Institute PAS

Original in:

Library of the Mossakowski Medical Research Institute PAS

Projects co-financed by:

Operational Program Digital Poland, 2014-2020, Measure 2.3: Digital accessibility and usefulness of public sector information; funds from the European Regional Development Fund and national co-financing from the state budget.

Access:

Open