scholarly journals Role of the Hyperpolarization‐Activated Cation Current ( I h ) in Pacemaker Activity in Area Postrema Neurons of Rat Brain Slices

2003 ◽  
Vol 552 (1) ◽  
pp. 135-148 ◽  
Author(s):  
Makoto Funahashi ◽  
Yoshihiro Mitoh ◽  
Atsushi Kohjitani ◽  
Ryuji Matsuo
Keyword(s):  
Rat Brain ◽  
Area Postrema ◽  
Brain Slices ◽  
Pacemaker Activity ◽  
Cation Current

scholarly journals The role of Ca2+ in the protoveratrine-induced release of γ-aminobutyrate from rat brain slices

1980 ◽  
Vol 190 (2) ◽  
pp. 333-339 ◽  
Author(s):  
M C W Minchin
Keyword(s):  
Cerebral Cortex ◽  
Rat Brain ◽  
Dose Response ◽  
Transmitter Release ◽  
Response Curve ◽  
Brain Slices ◽  
Veratrum Alkaloids ◽  
Similar Dose ◽  
22Na Uptake

1. Protoveratrine A increased the release of gamma-amino[3H]butyrate from small slices of rat cerebral cortex. This effect increased with increasing protoveratrine concentration, reaching a maximum at 100 microM. 2. Removal of Ca2+ from the superfusing medium did not change the increase in release due to 10 microM-protoveratrine; however, the Ca2+ antagonists, compound D-600, La3+, Mn2+, Mg2+ and also high Ca2+ concentration inhibited the effect of the alkaloid, as did procaine. 3. Protoveratrine A increased the uptake of 22Na+ into the slices with a similar dose-response curve to that found for gamma-aminobutyrate release. For the most part, the substances that inhibited protoveratrine-stimulated gamma-aminobutyrate release also inhibited 22Na+ uptake, although the correlation was not perfect. 4. Although extracellular Ca2+ is not required for protoveratrine-induced gamma-aminobutyrate release, an increase in Na+ influx that is susceptible to inhibition by some Ca2+ antagonists does appear to be associated with this phenomenon. However, the possibility remains that changes in the free intracellular Ca2+ concentration may be important for transmitter release induced by depolarizing veratrum alkaloids.

scholarly journals Effects of arginine-vasopressin on neuronal interaction from the area postrema to the nucleus tractus solitarii in rat brain slices

1998 ◽  
Vol 112 (supplement) ◽  
pp. 148-152
Author(s):  
Keisuke Migita ◽  
Nobuaki Hori ◽  
Ryo Saito ◽  
Kenji Honda ◽  
Yukio Takano ◽  
...  
Keyword(s):  
Rat Brain ◽  
Arginine Vasopressin ◽  
Area Postrema ◽  
Brain Slices ◽  
Nucleus Tractus Solitarii

Na+ influx-induced decrease of (Na++ K+) -ATPase activity in rat brain slices: role of Ca2+

1991 ◽  
Vol 204 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Matsuda Toshio ◽  
Shimizu Isao ◽  
Baba Akemichi
Keyword(s):  
Atpase Activity ◽  
Rat Brain ◽  
Brain Slices

Effects of arginine-vasopressin on neuronal interaction from the area postrema to the nucleus tractus solitarii in rat brain slices

1998 ◽  
Vol 256 (1) ◽  
pp. 45-48 ◽  
Author(s):  
Keisuke Migita ◽  
Nobuaki Hori ◽  
Jun-ichiro Manako ◽  
Ryo Saito ◽  
Yukio Takano ◽  
...  
Keyword(s):  
Rat Brain ◽  
Arginine Vasopressin ◽  
Area Postrema ◽  
Brain Slices ◽  
Nucleus Tractus Solitarii

scholarly journals Purinergic modulation of area postrema neuronal excitability in rat brain slices

2007 ◽  
Vol 1165 ◽  
pp. 50-59 ◽  
Author(s):  
Naoki Kodama ◽  
Makoto Funahashi ◽  
Yoshihiro Mitoh ◽  
Shogo Minagi ◽  
Ryuji Matsuo
Keyword(s):  
Rat Brain ◽  
Neuronal Excitability ◽  
Area Postrema ◽  
Brain Slices ◽  
Purinergic Modulation

scholarly journals Hyperpolarization-Activated Cation Current (Ih) Is an Ethanol Target in Midbrain Dopamine Neurons of Mice

2006 ◽  
Vol 95 (2) ◽  
pp. 619-626 ◽  
Author(s):  
Takashi Okamoto ◽  
Mark T. Harnett ◽  
Hitoshi Morikawa
Keyword(s):  
Firing Frequency ◽  
Dopamine Neurons ◽  
Pacemaker Activity ◽  
Activation Kinetics ◽  
Dopaminergic Transmission ◽  
Cation Current ◽  
Midbrain Dopamine ◽  
Maximum Conductance

Ethanol stimulates the firing activity of midbrain dopamine (DA) neurons, leading to enhanced dopaminergic transmission in the mesolimbic system. This effect is thought to underlie the behavioral reinforcement of alcohol intake. Ethanol has been shown to directly enhance the intrinsic pacemaker activity of DA neurons, yet the cellular mechanism mediating this excitation remains poorly understood. The hyperpolarization-activated cation current, Ih, is known to contribute to the pacemaker firing of DA neurons. To determine the role of Ih in ethanol excitation of DA neurons, we performed patch-clamp recordings in acutely prepared mouse midbrain slices. Superfusion of ethanol increased the spontaneous firing frequency of DA neurons in a reversible fashion. Treatment with ZD7288, a blocker of Ih, irreversibly depressed basal firing frequency and significantly attenuated the stimulatory effect of ethanol on firing. Furthermore, ethanol reversibly augmented Ih amplitude and accelerated its activation kinetics. This effect of ethanol was accompanied by a shift in the voltage dependence of Ih activation to more depolarized potentials and an increase in the maximum Ih conductance. Cyclic AMP mediated the depolarizing shift in Ih activation but not the increase in the maximum conductance. Finally, repeated ethanol treatment in vivo induced downregulation of Ih density in DA neurons and an accompanying reduction in the magnitude of ethanol stimulation of firing. These results suggest an important role of Ih in the reinforcing actions of ethanol and in the neuroadaptations underlying escalation of alcohol consumption associated with alcoholism.

Sign in / Sign up

Export Citation Format

Share Document