Objective　To study the effects of hypoxia and glutamic acid on the kinetic properties of NMDA receptor channel of the hypothalamic neurons in rats. Methods　Cell-attached mode patch clamp technique was employed to record the single channel current of the NMDA receptor. Results　The open probability of NMDA receptor channel was increased after acute hypoxia compared with that of normal state, the open time τ1,τ2 was changed from (0.33±0.10)ms，(4.36±0.26)ms to (0.93±0.22)ms，(7.64±0.72)ms, and the close time τ1,τ2 was from (18.03±3.50)ms，(171.50±19.10)ms to (3.42±1.02)ms，(19.39±3.07)ms. The mean open probability was changed from 0.12±0.05 in normal state to 0.66±0.36 in hypoxia state. Furthermore, glutamic acid can increase open time and open probability of NMDA receptor channel,decrease close time. Conclusion　The excitability and the open probability of NMDA receptor channel of hypothalamic neurons increased by hypoxia is related to glutamate.

AIMTo study the effect of fetus hypobaric hypoxia on the number and channel character of NMDA receptor of hippocampus neurons.

METHODSUse in situ hybridization and patch-clamp techniques.

RESULTSAfter hypobaric hypoxia the number of NMDA mRNA positive neurons was decreased, the open probability of NMDA receptor was reduced, the open time constant was decreased, the close time constant was increased.

CONCLUSIONHypobaric hypoxia may change the development of NMDA receptor in fetus rat, then maybe effect learning and memory.

Animals ; Cell Hypoxia ; Fetus ; physiopathology ; Hippocampus ; cytology ; physiopathology ; In Situ Hybridization ; Intracranial Hypotension ; physiopathology ; N-Methylaspartate ; metabolism ; Neurons ; pathology ; Patch-Clamp Techniques ; RNA, Messenger ; genetics ; Rats ; Receptors, N-Methyl-D-Aspartate ; metabolism

AIMTo develop simple but reliable intracellular labelling method for high-resolution visualization of the fine structure of single neurons in brain slice with thickness of 500 microm.

METHODSBiocytin was introduced into neurons in 500 microm-thickness brain slices while blind whole cell recording. Following processed for histochemistry using the avidin-biotin-complex method, stained slices were mounted in glycerol on special glass slides. Labelled cells were digital photomicrographed every 30 microm and reconstructed with Adobe Photoshop software.

RESULTSAfter histochemistry, limited background staining was produced. The resolution was so high that fine structure, including branching, termination of individual axons and even spines of neurons could be identified in exquisite detail with optic microscope. With the help of software, the neurons of interest could be reconstructed from a stack of photomicrographs.

CONCLUSIONThe modified method provides an easy and reliable approach to revealing the detailed morphological properties of single neurons in 500 microm-thickness brain slice. Without requisition of special equipment, it is suited to be broadly applied.

Animals ; Image Processing, Computer-Assisted ; Neurons ; cytology ; physiology ; Patch-Clamp Techniques ; Rats ; Rats, Sprague-Dawley ; Software ; Staining and Labeling ; methods

Actins ; metabolism ; Animals ; Brain ; cytology ; metabolism ; Cell Culture Techniques ; methods ; Cells, Cultured ; Immunohistochemistry ; Pericytes ; cytology ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, Platelet-Derived Growth Factor beta ; metabolism ; Staining and Labeling

In order to investigate the central nervous mechanism and the diseases involved in catecholamine transmitter secretion, the dynamics of catecholamine release is studied in single cell, brain slice or in vivo. Noradrenaline is an important neurotransmitter and modulator in the central nervous system (CNS) and the peripheral nervous system (PNS). In the present paper, we first compared three real-time methods used to measure noradrenaline secretion in single cells (membrane capacitance, amperometry and confocal fluorescence microscopy imaging). Compared to the electrophysiological method and fluorescence microscopy, the basic usage of the carbon fiber electrode (CFE) in neuroscience research was presented as an example. Then, we presented a primary description of ion channels, including voltage-gated Na(+), K(+) and Ca(2+) channels in locus coeruleus (LC) neurons in rat brain slices. Finally, we presented example recordings of combined patch-clamp and amperometry measurements in LC neurons, indicating Ca(2+)-dependent quantal noradrenaline release following Ca(2+) influx through Ca(2+) channels.
Animals ; Central Nervous System ; physiology ; Ion Channels ; physiology ; Norepinephrine ; secretion ; Patch-Clamp Techniques ; Rats