Activation of α-adrenoceptors depresses synaptic transmission of myelinated afferents and inhibits pathways mediating primary afferent depolarization (PAD) in the in vitro mouse spinal cord.
Activation of α-adrenoceptors depresses synaptic transmission of myelinated afferents and inhibits pathways mediating primary afferent depolarization (PAD) in the in vitro mouse spinal cord.
复制标题
α-肾上腺素受体的激活抑制有髓传入神经的突触传递，并抑制体外小鼠脊髓中介导初级传入去极化 (PAD) 的途径。
DOI：
10.1007/s00221-020-05805-y
复制
发表时间：
2020
影响因子：
2
通讯作者：
Quevedo,JorgeN
中科院分区：
文献类型：
--
作者：
Mena-Avila,Elvia;Milla-Cruz,JonathanJ;Calvo,JorgeR;Hochman,Shawn;Villalón,CarlosM;Arias-Montaño,José-Antonio;Quevedo,JorgeN
Somatosensory afferent transmission strength is controlled by several presynaptic mechanisms that reduce transmitter release at the spinal cord level. We focused this investigation on the role of α-adrenoceptors in modulating sensory transmission in low-threshold myelinated afferents and in pathways mediating primary afferent depolarization (PAD) of neonatal mouse spinal cord. We hypothesized that the activation of α-adrenoceptors depresses low threshold-evoked synaptic transmission and inhibits pathways mediating PAD. Extracellular field potentials (EFPs) recorded in the deep dorsal horn assessed adrenergic modulation of population monosynaptic transmission, while dorsal root potentials (DRPs) recorded at root entry zone assessed adrenergic modulation of PAD. We found that noradrenaline (NA) and the α1-adrenoceptor agonists phenylephrine and cirazoline depressed synaptic transmission (by 15, 14 and 22%, respectively). DRPs were also depressed by NA, phenylephrine and cirazoline (by 62, 30, and 64%, respectively), and by the α2-adrenoceptor agonist clonidine, although to a lower extent (20%). We conclude that NA depresses monosynaptic transmission of myelinated afferents onto deep dorsal horn neurons via α1-adrenoceptors and inhibits interneuronal pathways mediating PAD through the activation of α1- and α2-adrenoceptors. The functional significance of these modulatory actions in shaping cutaneous and muscle sensory information during motor behaviors requires further study.
