Biomaterial Database

Neurophysiological changes of spiny neurons in rat neostriatum after transient forebrain ischemia: an in vivo intracellular recording and staining study. 1995

Z C Xu

Department of Neurology, College of Medicine, University of Tennessee, Memphis 38163, USA.

The spontaneous activities, evoked postsynaptic potentials and membrane properties of spiny neurons in rat neostriatum were compared before, during and after 5-8 min ischemia using intracellular recording and staining techniques in vivo. Severe forebrain ischemia was induced with the four-vessel occlusion method. Approximately 2.5 min after the onset of ischemia the baseline membrane potential quickly depolarized to -20 mV and remained at this level during ischemia. Repolarization began within 2 min after recirculation. The onset of ischemic depolarization was directly related to the severity of ischemia and its latency was inversely related to brain temperature. Spontaneous firing and membrane potential fluctuation of spiny neurons ceased immediately after ischemia and slowly recovered several hours after recirculation. No neuronal hyperactivity was observed up to 7 h after recirculation. Cortically evoked inhibitory postsynaptic potentials and late depolarizations disappeared earlier after ischemia and recovered later following recirculation than the initial excitatory postsynaptic potentials. Membrane input resistance of spiny neurons was significantly increased but the time constant remained the same following recirculation. The rheobase and spike threshold of spiny neurons were significantly increased and the repetitive firing evoked by depolarizing current pulse was suppressed shortly after recirculation. The results of the present study indicated that the spontaneous activity and evoked postsynaptic responses of spiny neurons are suppressed and the excitability of spiny neurons is decreased after transient ischemia. The polysynaptic responses are more sensitive to ischemia than the monosynaptic ones.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D002545	Brain Ischemia	Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia (HYPOXIA, BRAIN). Prolonged ischemia is associated with BRAIN INFARCTION.	Cerebral Ischemia,Ischemic Encephalopathy,Encephalopathy, Ischemic,Ischemia, Cerebral,Brain Ischemias,Cerebral Ischemias,Ischemia, Brain,Ischemias, Cerebral,Ischemic Encephalopathies
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D006221	Halothane	A nonflammable, halogenated, hydrocarbon anesthetic that provides relatively rapid induction with little or no excitement. Analgesia may not be adequate. NITROUS OXIDE is often given concomitantly. Because halothane may not produce sufficient muscle relaxation, supplemental neuromuscular blocking agents may be required. (From AMA Drug Evaluations Annual, 1994, p178)	1,1,1-Trifluoro-2-Chloro-2-Bromoethane,Fluothane,Ftorotan,Narcotan
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013194	Staining and Labeling	The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.	Histological Labeling,Staining,Histological Labelings,Labeling and Staining,Labeling, Histological,Labelings, Histological,Stainings
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D017072	Neostriatum	The phylogenetically newer part of the CORPUS STRIATUM consisting of the CAUDATE NUCLEUS and PUTAMEN. It is often called simply the striatum.