Gap Junctions Contribute to Ictal/Interictal Genesis in Human Hypothalamic Hamartomas

Jie Wu, Ming Gao, Stephen G. Rice, Candy Tsang, John Beggs, Dharshaun Turner, Guohui Li, Bo Yang, Kunkun Xia, Fenfei Gao, Shenfeng Qiu, Qiang Liu, John F. Kerrigan

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Human hypothalamic hamartoma (HH) is a rare subcortical lesion associated with treatment-resistant epilepsy. Cellular mechanisms responsible for epileptogenesis are unknown. We hypothesized that neuronal gap junctions contribute to epileptogenesis through synchronous activity within the neuron networks in HH tissue. We studied surgically resected HH tissue with Western-blot analysis, immunohistochemistry, electron microscopy, biocytin microinjection of recorded HH neurons, and microelectrode patch clamp recordings with and without pharmacological blockade of gap junctions. Normal human hypothalamus tissue was used as a control. Western blots showed increased expression of both connexin-36 (Cx36) and connexin-43 (Cx43) in HH tissue compared with normal human mammillary body tissue. Immunohistochemistry demonstrated that Cx36 and Cx43 are expressed in HH tissue, but Cx36 was mainly expressed within neuron clusters while Cx43 was mainly expressed outside of neuron clusters. Gap-junction profiles were observed between small HH neurons with electron microscopy. Biocytin injection into single recorded small HH neurons showed labeling of adjacent neurons, which was not observed in the presence of a neuronal gap-junction blocker, mefloquine. Microelectrode field recordings from freshly resected HH slices demonstrated spontaneous ictal/interictal-like discharges in most slices. Bath-application of gap-junction blockers significantly reduced ictal/interictal-like discharges in a concentration-dependent manner, while not affecting the action-potential firing of small gamma-aminobutyric acid (GABA) neurons observed with whole-cell patch-clamp recordings from the same patient's HH tissue. These results suggest that neuronal gap junctions between small GABAergic HH neurons participate in the genesis of epileptic-like discharges. Blockade of gap junctions may be a new therapeutic strategy for controlling seizure activity in HH patients.

Original languageEnglish (US)
JournalEBioMedicine
DOIs
StateAccepted/In press - Feb 20 2016

Fingerprint

Gap Junctions
Neurons
Stroke
Tissue
Connexin 43
Electrical Synapses
Microelectrodes
Clamping devices
Electron microscopy
Mefloquine
Hypothalamic hamartomas
Electron Microscopy
Western Blotting
Immunohistochemistry
Mammillary Bodies
gamma-Aminobutyric Acid
Labeling
Microinjections
Baths
Human Body

Keywords

  • Gap junction
  • Gelastic seizures
  • Human epilepsy
  • Hypothalamic hamartoma
  • Patch-clamp

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Cite this

Wu, J., Gao, M., Rice, S. G., Tsang, C., Beggs, J., Turner, D., ... Kerrigan, J. F. (Accepted/In press). Gap Junctions Contribute to Ictal/Interictal Genesis in Human Hypothalamic Hamartomas. EBioMedicine. https://doi.org/10.1016/j.ebiom.2016.04.026

Gap Junctions Contribute to Ictal/Interictal Genesis in Human Hypothalamic Hamartomas. / Wu, Jie; Gao, Ming; Rice, Stephen G.; Tsang, Candy; Beggs, John; Turner, Dharshaun; Li, Guohui; Yang, Bo; Xia, Kunkun; Gao, Fenfei; Qiu, Shenfeng; Liu, Qiang; Kerrigan, John F.

In: EBioMedicine, 20.02.2016.

Research output: Contribution to journalArticle

Wu, J, Gao, M, Rice, SG, Tsang, C, Beggs, J, Turner, D, Li, G, Yang, B, Xia, K, Gao, F, Qiu, S, Liu, Q & Kerrigan, JF 2016, 'Gap Junctions Contribute to Ictal/Interictal Genesis in Human Hypothalamic Hamartomas', EBioMedicine. https://doi.org/10.1016/j.ebiom.2016.04.026
Wu, Jie ; Gao, Ming ; Rice, Stephen G. ; Tsang, Candy ; Beggs, John ; Turner, Dharshaun ; Li, Guohui ; Yang, Bo ; Xia, Kunkun ; Gao, Fenfei ; Qiu, Shenfeng ; Liu, Qiang ; Kerrigan, John F. / Gap Junctions Contribute to Ictal/Interictal Genesis in Human Hypothalamic Hamartomas. In: EBioMedicine. 2016.
@article{f9574f99df244f7f87b0577eaedb90e6,
title = "Gap Junctions Contribute to Ictal/Interictal Genesis in Human Hypothalamic Hamartomas",
abstract = "Human hypothalamic hamartoma (HH) is a rare subcortical lesion associated with treatment-resistant epilepsy. Cellular mechanisms responsible for epileptogenesis are unknown. We hypothesized that neuronal gap junctions contribute to epileptogenesis through synchronous activity within the neuron networks in HH tissue. We studied surgically resected HH tissue with Western-blot analysis, immunohistochemistry, electron microscopy, biocytin microinjection of recorded HH neurons, and microelectrode patch clamp recordings with and without pharmacological blockade of gap junctions. Normal human hypothalamus tissue was used as a control. Western blots showed increased expression of both connexin-36 (Cx36) and connexin-43 (Cx43) in HH tissue compared with normal human mammillary body tissue. Immunohistochemistry demonstrated that Cx36 and Cx43 are expressed in HH tissue, but Cx36 was mainly expressed within neuron clusters while Cx43 was mainly expressed outside of neuron clusters. Gap-junction profiles were observed between small HH neurons with electron microscopy. Biocytin injection into single recorded small HH neurons showed labeling of adjacent neurons, which was not observed in the presence of a neuronal gap-junction blocker, mefloquine. Microelectrode field recordings from freshly resected HH slices demonstrated spontaneous ictal/interictal-like discharges in most slices. Bath-application of gap-junction blockers significantly reduced ictal/interictal-like discharges in a concentration-dependent manner, while not affecting the action-potential firing of small gamma-aminobutyric acid (GABA) neurons observed with whole-cell patch-clamp recordings from the same patient's HH tissue. These results suggest that neuronal gap junctions between small GABAergic HH neurons participate in the genesis of epileptic-like discharges. Blockade of gap junctions may be a new therapeutic strategy for controlling seizure activity in HH patients.",
keywords = "Gap junction, Gelastic seizures, Human epilepsy, Hypothalamic hamartoma, Patch-clamp",
author = "Jie Wu and Ming Gao and Rice, {Stephen G.} and Candy Tsang and John Beggs and Dharshaun Turner and Guohui Li and Bo Yang and Kunkun Xia and Fenfei Gao and Shenfeng Qiu and Qiang Liu and Kerrigan, {John F.}",
year = "2016",
month = "2",
day = "20",
doi = "10.1016/j.ebiom.2016.04.026",
language = "English (US)",
journal = "EBioMedicine",
issn = "2352-3964",
publisher = "Elsevier BV",

}

TY - JOUR

T1 - Gap Junctions Contribute to Ictal/Interictal Genesis in Human Hypothalamic Hamartomas

AU - Wu, Jie

AU - Gao, Ming

AU - Rice, Stephen G.

AU - Tsang, Candy

AU - Beggs, John

AU - Turner, Dharshaun

AU - Li, Guohui

AU - Yang, Bo

AU - Xia, Kunkun

AU - Gao, Fenfei

AU - Qiu, Shenfeng

AU - Liu, Qiang

AU - Kerrigan, John F.

PY - 2016/2/20

Y1 - 2016/2/20

N2 - Human hypothalamic hamartoma (HH) is a rare subcortical lesion associated with treatment-resistant epilepsy. Cellular mechanisms responsible for epileptogenesis are unknown. We hypothesized that neuronal gap junctions contribute to epileptogenesis through synchronous activity within the neuron networks in HH tissue. We studied surgically resected HH tissue with Western-blot analysis, immunohistochemistry, electron microscopy, biocytin microinjection of recorded HH neurons, and microelectrode patch clamp recordings with and without pharmacological blockade of gap junctions. Normal human hypothalamus tissue was used as a control. Western blots showed increased expression of both connexin-36 (Cx36) and connexin-43 (Cx43) in HH tissue compared with normal human mammillary body tissue. Immunohistochemistry demonstrated that Cx36 and Cx43 are expressed in HH tissue, but Cx36 was mainly expressed within neuron clusters while Cx43 was mainly expressed outside of neuron clusters. Gap-junction profiles were observed between small HH neurons with electron microscopy. Biocytin injection into single recorded small HH neurons showed labeling of adjacent neurons, which was not observed in the presence of a neuronal gap-junction blocker, mefloquine. Microelectrode field recordings from freshly resected HH slices demonstrated spontaneous ictal/interictal-like discharges in most slices. Bath-application of gap-junction blockers significantly reduced ictal/interictal-like discharges in a concentration-dependent manner, while not affecting the action-potential firing of small gamma-aminobutyric acid (GABA) neurons observed with whole-cell patch-clamp recordings from the same patient's HH tissue. These results suggest that neuronal gap junctions between small GABAergic HH neurons participate in the genesis of epileptic-like discharges. Blockade of gap junctions may be a new therapeutic strategy for controlling seizure activity in HH patients.

AB - Human hypothalamic hamartoma (HH) is a rare subcortical lesion associated with treatment-resistant epilepsy. Cellular mechanisms responsible for epileptogenesis are unknown. We hypothesized that neuronal gap junctions contribute to epileptogenesis through synchronous activity within the neuron networks in HH tissue. We studied surgically resected HH tissue with Western-blot analysis, immunohistochemistry, electron microscopy, biocytin microinjection of recorded HH neurons, and microelectrode patch clamp recordings with and without pharmacological blockade of gap junctions. Normal human hypothalamus tissue was used as a control. Western blots showed increased expression of both connexin-36 (Cx36) and connexin-43 (Cx43) in HH tissue compared with normal human mammillary body tissue. Immunohistochemistry demonstrated that Cx36 and Cx43 are expressed in HH tissue, but Cx36 was mainly expressed within neuron clusters while Cx43 was mainly expressed outside of neuron clusters. Gap-junction profiles were observed between small HH neurons with electron microscopy. Biocytin injection into single recorded small HH neurons showed labeling of adjacent neurons, which was not observed in the presence of a neuronal gap-junction blocker, mefloquine. Microelectrode field recordings from freshly resected HH slices demonstrated spontaneous ictal/interictal-like discharges in most slices. Bath-application of gap-junction blockers significantly reduced ictal/interictal-like discharges in a concentration-dependent manner, while not affecting the action-potential firing of small gamma-aminobutyric acid (GABA) neurons observed with whole-cell patch-clamp recordings from the same patient's HH tissue. These results suggest that neuronal gap junctions between small GABAergic HH neurons participate in the genesis of epileptic-like discharges. Blockade of gap junctions may be a new therapeutic strategy for controlling seizure activity in HH patients.

KW - Gap junction

KW - Gelastic seizures

KW - Human epilepsy

KW - Hypothalamic hamartoma

KW - Patch-clamp

UR - http://www.scopus.com/inward/record.url?scp=84967188772&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84967188772&partnerID=8YFLogxK

U2 - 10.1016/j.ebiom.2016.04.026

DO - 10.1016/j.ebiom.2016.04.026

M3 - Article

JO - EBioMedicine

JF - EBioMedicine

SN - 2352-3964

ER -