Upregulated TWIK-related acid-sensitive K+ channel-2 in neurons and perivascular astrocytes in the hippocampus of experimental temporal lobe epilepsy.
OBJECTIVE
To identify the modulation of Tandem of P-domains in a weak inwardly rectifying K(+) channel (TWIK)-related acid-sensitive K(+) (TASK)-2 channel expressions in epilepsy, we conducted a comparative analysis of TASK-2 channel immunoreactivity in the hippocampus of a pilocarpine-induced rat epilepsy model.


METHODS
We performed and immunohistochemical study for TASK-2 and double immunofluorescent staining for TASK-2 and glial fibrillary acidic protein (GFAP) in the rat hippocampus of pilocarpine-induced epilepsy models.


RESULTS
In control animals, TASK-2 immunoreactivity was strongly detected in CA1-3 pyramidal layers and dentate granule cell layer. After status epilepticus (SE), TASK-2 immunoreactivity was increased in dentate granule cell layer and CA3 pyramidal cell layer, whereas its immunoreactivity was reduced in CA1 pyramidal cell layer. In addition, TASK-2 immunoreactivity is gradually increased in perivascular regions following SE. Double immunofluorescent study revealed that the enhancement of TASK-2 immunoreactivity in perivascular regions is caused by increase in the number of TASK-2 immunoreactive endfeet of perivascular astrocytes.


CONCLUSIONS
Our findings suggest that elevated TASK-2 immunoreactivity in neurons may contribute to rapid adaptive responses (presumably for extracellular alkalinization), which result in hyperpolarization and regulate seizure activity. In contrast, upregulated TASK-2 immunoreactivity in perivascular regions may be involved in abnormalities of blood flow regulation or brain-blood barrier impairment. These changes may contribute to acquisition of the properties of the epileptic hippocampus.
Kim
Ji-Eun
JE
Department of Anatomy and Neurobiology and Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon, South Korea.
Kwak
Sung-Eun
SE
Kang
Tae-Cheon
TC
D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D001286:Atropine Derivatives; D002552:Cerebral Ventricles / Q000473:pathology*; D004195:Disease Models, Animal; D004833:Epilepsy, Temporal Lobe / Q000139:chemically induced / Q000473:pathology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D007211:Indoles; D008297:Male; D009474:Neurons / Q000378:metabolism*; D010862:Pilocarpine; D024683:Potassium Channels, Tandem Pore Domain / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology*
D001286:Atropine Derivatives; D005904:Glial Fibrillary Acidic Protein; D007211:Indoles; C498740:Kcnk5 protein, rat; D024683:Potassium Channels, Tandem Pore Domain; D010862:Pilocarpine; C007293:DAPI; C006649:methylatropine