Effects of carnosine on the evoked potentials in hippocampal CA1 region.
OBJECTIVE
To directly examine the effects of carnosine on neuronal excitation and inhibition in rat hippocampus in vivo.


METHODS
Artificial cerebrospinal fluid with carnosine was directly administrated over the exposed rat hippocampus. The changes of neuron activity in the CA1 region of hippocampus were evaluated by orthodromically- and antidromically-evoked potentials, as well as paired-pulse stimulation paradigm.


RESULTS
In both orthodromic and antidromic response potentials, carnosine transformed population spikes (PSs) with single spike into epileptiform multiple spikes. In addition, similar to the effect of (-aminobutyric acid(A) (GABA(A)) antagonist picrotoxin, carnosine decreased paired-pulse stimulating depression significantly. However, no significant change was observed in the spontaneous field potentials during the application of carnosine.


CONCLUSIONS
The results indicate a disinhibition-induced excitation effect of carnosine on the CA1 pyramidal neurons. It provides important information against the application of carnosine as a potential anticonvulsant in clinical treatment.
Feng
Zhou-Yan
ZY
Key Lab of Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310003, China. hnfzy@yahoo.com.cn
Zheng
Xiao-Jing
XJ
Wang
Jing
J
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D002336:Carnosine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D002336:Carnosine