Hypoxia in striatal and cortical neurones: membrane potential and Ca2+ measurements.
Simultaneous measurements of membrane potential and intracellular Ca2+ were used to study the effects of hypoxia on striatal and cortical neurones. Striatal neurones responded to hypoxia with a reversible membrane depolarization coupled with a transient increase in intracellular Ca2+. Thirty minutes of hypoxia caused an irreversible membrane depolarization associated with a massive raise in Ca2+ levels, leading to cell death. Conversely, cortical neurones were more resistant to O2 deprivation. Hypoxia (4-10 min) induced minimal changes in both membrane potential and Ca2+ signals. Longer periods (20-30 min) caused an initial membrane hyperpolarization followed by a large but reversible depolarization coupled with a transient increase in Ca2+ signals. These results support the hypothesis of a differential sensitivity of central neurones to hypoxia, suggesting that striatal neurones are more vulnerable than cortical cells.
Pisani
A
A
Dipartimento Sanità, Università Tor Vergata, Rome, Italy.
Calabresi
P
P
Bernardi
G
G
D000818:Animals; D015220:Calcium Channels / Q000502:physiology*; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology*; D003342:Corpus Striatum / Q000473:pathology / Q000503:physiopathology*; D002534:Hypoxia, Brain / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
D015220:Calcium Channels