title: KCa1.1 is potential marker for distinguishing Ah-type baroreceptor neurons in NTS and contributes to sex-specific presynaptic neurotransmission in baroreflex afferent pathway.
abstract: Sexual-dimorphic neurocontrol of circulation has been described in baroreflex due largely to the function of myelinated Ah-type baroreceptor neurons (BRNs, 1st-order) in nodose. However, it remains unclear if sex- and afferent-specific neurotransmission could also be observed in the central synapses within nucleus of solitary track (NTS, 2nd-order). According to the principle of no mixed neurotransmission among afferents and differentiation of Ah- and A-types to iberiotoxin (IbTX) observed in nodose, the 2nd-order Ah-type BRNs are highly expected. To test this hypothesis, the excitatory post-synaptic currents (EPSCs) were recorded in identified 2nd-order BRNs before and after IbTX using brain slice and whole-cell patch. These results showed that, in male rats, the dynamics of EPSCs in capsaicin-sensitive C-types were dramatically altered by IbTX, but not in capsaicin-insensitive A-types. Interestingly, near 50% capsaicin-insensitive neurons in females showed similar effects to C-types, suggesting the existence of Ah-types in NTS, which may be the likely reason why the females had lower blood pressure and higher sensitivity to aortic depressor nerve stimulation via KCa1.1-mediated presynaptic glutamate release from Ah-type afferent terminals.
authors.affiliation: Department of Anatomy, Histology, and Embryology, Heilongjiang University of Chinese Medicine, Harbin, China; Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, China.
authors.forename: Yu-Yao
authors.initials: YY
authors.lastname: Zhang
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China.
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Yan
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China.
authors.forename: Mei-Yu
authors.initials: MY
authors.lastname: Qu
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China.
authors.forename: Xin-Jing
authors.initials: XJ
authors.lastname: Guo
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China.
authors.forename: Guo
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China.
authors.forename: Xiao-Long
authors.initials: XL
authors.lastname: Lu
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China; Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Ban
authors.affiliation: Department of Pharmacology, Da-Qing Campus of Harbin Medical University, Da-Qing, China.
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Sun
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China; Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, China. Electronic address: qiaogf88@163.com.
authors.forename: Guo-Fen
authors.initials: GF
authors.lastname: Qiao
authors.affiliation: Department of Pharmacology, Harbin Medical University, Harbin, China. Electronic address: liby@ems.hrbmu.edu.cn.
authors.forename: Bai-Yan
authors.initials: BY
authors.lastname: Li
mesh_terms: D000344:Afferent Pathways; D000818:Animals; D001011:Aorta / Q000294:innervation; D001933:Brain Stem / Q000502:physiology*; D002211:Capsaicin / Q000494:pharmacology; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials; D005260:Female; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits / Q000502:physiology*; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000502:physiology; D036421:Nerve Fibers, Unmyelinated / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D010455:Peptides / Q000494:pharmacology; D011311:Pressoreceptors / Q000378:metabolism*; D017207:Rats, Sprague-Dawley; D012737:Sex Factors; D017552:Solitary Nucleus / Q000502:physiology; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission
chemical_list: C494842:Kcnma1 protein, rat; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D010455:Peptides; C064719:iberiotoxin; D002211:Capsaicin
keywords: Baroreflex; Excitatory post-synaptic current (EPSC); Gender difference; Nucleus tractus solitary (NTS); Visceral afferent