title: Myelinated Ah-type trigeminal ganglion neurons in female rats: neuroexcitability, chemosensitivity to histamine, and potential clinical impact.
abstract: Migraine is a chronic neurological disorder characterized by recurrent moderate-to-severe headaches often associated with numerous autonomic nervous system symptoms, and it is more prevalent in women. To fully understand the underlying mechanism, standard electrophysiology was performed with trigeminal ganglion neurons (TGNs) isolated from adult rats of both genders using the whole-cell patch clamp technique to test the distribution, neuroexcitability, and chemosensitivity to histamine. In addition to traditionally classified A- and C-type TGNs, myelinated Ah-type TGNs were also observed in females. The electrophysiological features showed low firing threshold and the capability to fire repetitively upon stimulation. Ah-type neurons also functionally expressed persistent TTX-R Na(+) channels with more hyperpolarized activating voltage. Iberiotoxin and NS11021 significantly altered the discharge profiles of Ah-type TGNs. Finally, Ah-type TGNs showed a more potent reaction to histamine, with relatively larger inward currents and membrane depolarization compared with C-types. These data provide evidence of the gender-specific distribution of myelinated Ah-type TGNs in adult female rats, characterized by a low threshold and high frequency of firing that are at least partially attributable to persistent TTX-R Na(+) and BK-KCa channel expression and potent chemosensitivity to histamine, suggesting that Ah-type TGNs may play a key role in gender differences in migraine.
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China; Department of Neurology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Xin
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Wei
authors.initials: W
authors.lastname: He
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, China. Electronic address: zhiqiangsu2013@163.com.
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Su
mesh_terms: D000200:Action Potentials; D000818:Animals; D005260:Female; D006632:Histamine / Q000494:pharmacology* / Q000502:physiology; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000502:physiology; D008297:Male; D009186:Myelin Sheath / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D017207:Rats, Sprague-Dawley; D011984:Sensory Receptor Cells / Q000502:physiology*; D012737:Sex Factors; D012668:Trigeminal Ganglion / Q000166:cytology / Q000502:physiology*; D061566:Voltage-Gated Sodium Channels / Q000502:physiology
chemical_list: D051036:Large-Conductance Calcium-Activated Potassium Channels; D061566:Voltage-Gated Sodium Channels; D006632:Histamine
keywords: Ion channel; Myelination; Neuroexcitability; Trigeminal ganglion neuron; Whole-cell patch