GABA is depolarizing in hippocampal dentate granule cells of the adolescent and adult rats.
GABAergic signaling in hippocampal pyramidal neurons undergoes a switch from depolarizing to hyperpolarizing during early neuronal development. Whether such a transformation of GABAergic action occurs in dentate granule cells (DGCs), located at the first stage of the hippocampal trisynaptic circuit, is unclear. Here, we use noninvasive extracellular recording to monitor the effect of synaptically released GABA on the DGC population. We find that GABAergic responses in adolescent and adult rat DGCs are still depolarizing from rest. Using a morphologically realistic DGC model, we show that GABAergic action, depending on its precise timing and location, can have either an excitatory or inhibitory role in signal processing in the dentate gyrus.
Institute of Neuroscience and Brain Research Center, School of Life Sciences, National Yang-Ming University, Taipei 112, Taiwan.
Po-Han
PH
Chiang
Pu-Yeh
PY
Wu
Tzu-Wei
TW
Kuo
Yu-Chao
YC
Liu
Chu-Fang
CF
Chan
Ta-Chun
TC
Chien
Jen-Kun
JK
Cheng
Yu-Yin
YY
Huang
Cheng-Di
CD
Chiu
Cheng-Chang
CC
Lien
D000200:Action Potentials / Q000502:physiology*; D000375:Aging / Q000502:physiology; D000818:Animals; D018891:Dentate Gyrus / Q000166:cytology / Q000254:growth & development*; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D005680:gamma-Aminobutyric Acid