Effects of GABA on presynaptic nerve terminals in bullfrog (Rana catesbiana) sympathetic ganglia

1974 ◽  
Vol 30 (4) ◽  
pp. 382-383 ◽  
Author(s):  
K. Koketsu ◽  
T. Shoji ◽  
K. Yamamoto
Keyword(s):  
Sympathetic Ganglia ◽  
Nerve Terminals ◽  
Presynaptic Nerve Terminals

Role of sodium-calcium exchange in regulation of intracellular calcium in nerve terminals

1987 ◽  
Vol 252 (6) ◽  
pp. C595-C603 ◽  
Author(s):  
S. Sanchez-Armass ◽  
M. P. Blaustein
Keyword(s):  
Hill Coefficient ◽  
Nerve Terminals ◽  
Physiological Load ◽  
Carbonyl Cyanide ◽  
Ca Uptake ◽  
Na Ions ◽  
Presynaptic Nerve Terminals ◽  
45Ca Efflux ◽  
Mitochondrial Uncoupler

Ca efflux from rat brain presynaptic nerve terminals (synaptosomes) was examined after loading the terminals with 45Ca during a brief depolarization, usually in media containing 20 microM Ca labeled with 45Ca, to assure a small (physiological) load. Efflux of 45Ca was very slow in the absence of external Na and Ca (approximately 0.5% of the load/s) and was greatly accelerated by Na and/or Ca (presumably Na+-Ca2+ and Ca2+-Ca2+ exchange, respectively). The dependence of 45Ca efflux on external Na was sigmoid, with a Hill coefficient of approximately 2.5; this implies that more than two external Na ions are required to activate the efflux of one Ca ion. The external Na (Nao)-dependent Ca efflux was inhibited by 1 mM external La, by low temperature (Q10 congruent to 2.3), and by raising external K (to depolarize the synaptosomes). With small Ca loads, the mitochondrial uncoupler, carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP), had negligible effect on either Ca uptake or efflux; with large loads (greater than or equal to 5 nmol/mg protein), however, FCCP reduced the depolarization-stimulated Ca uptake and increased the Nao-dependent Ca efflux. These effects may be attributed to reduction of mitochondrial Ca sequestration. Mitochondria do not appear to sequester much Ca when the loads are smaller (and more physiological). Estimations of Ca efflux indicate that approximately 20% of a small 45Ca load (approximately 0.75 nmol Ca/mg protein) may be extruded via Na+-Ca2+ exchange within 1 s; this corresponds to a net Ca efflux of approximately 110 pmol Ca X mg protein-1 X s-1.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals TMEM16B regulates anxiety-related behavior and GABAergic neuronal signaling in the central lateral amygdala

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Ke-Xin Li ◽  
Mu He ◽  
Wenlei Ye ◽  
Jeffrey Simms ◽  
Michael Gill ◽  
...  
Keyword(s):  
Action Potential ◽  
Knockout Mice ◽  
Chloride Channel ◽  
Action Potential Duration ◽  
Fear Memory ◽  
Brain Regions ◽  
Gabaergic Neurons ◽  
Nerve Terminals ◽  
Lateral Amygdala ◽  
Presynaptic Nerve Terminals

TMEM16B (ANO2) is the Ca2+-activated chloride channel expressed in multiple brain regions, including the amygdala. Here we report that Ano2 knockout mice exhibit impaired anxiety-related behaviors and context-independent fear memory, thus implicating TMEM16B in anxiety modulation. We found that TMEM16B is expressed in somatostatin-positive (SOM+) GABAergic neurons of the central lateral amygdala (CeL), and its activity modulates action potential duration and inhibitory postsynaptic current (IPSC). We further provide evidence for TMEM16B actions not only in the soma but also in the presynaptic nerve terminals of GABAergic neurons. Our study reveals an intriguing role for TMEM16B in context-independent but not context-dependent fear memory, and supports the notion that dysfunction of the amygdala contributes to anxiety-related behaviors.

scholarly journals Direct Recording of Nicotinic Responses in Presynaptic Nerve Terminals

1997 ◽  
Vol 17 (15) ◽  
pp. 5798-5806 ◽  
Author(s):  
Jay S. Coggan ◽  
Jacques Paysan ◽  
William G. Conroy ◽  
Darwin K. Berg
Keyword(s):  
Nerve Terminals ◽  
Direct Recording ◽  
Presynaptic Nerve Terminals
Sign in / Sign up

Export Citation Format

Share Document