Neuromodulation using ultra low frequency current waveform reversibly blocks axonal conduction and chronic pain.

Chronic pain remains a leading cause of disability worldwide, and there is still a clinical reliance on opioids despite the medical side effects associated with their use and societal impacts associated with their abuse. An alternative approach is the use of electrical neuromodulation to produce analgesia. Direct current can block action potential propagation but leads to tissue damage if maintained.

Cortical Mechanisms of Single-Pulse Transcranial Magnetic Stimulation in Migraine.

Single-pulse transcranial magnetic stimulation (sTMS) of the occipital cortex is an effective migraine treatment. However, its mechanism of action and cortical effects of sTMS in migraine are yet to be elucidated. Using calcium imaging and GCaMP-expressing mice, sTMS did not depolarise neurons and had no effect on vascular tone.

A role for nerve growth factor in sympathetic sprouting in rat dorsal root ganglia.

The role of nerve growth factor (NGF) and glial-derived neurotrophic factor (GDNF) in sympathetic sprouting within the dorsal root ganglion was investigated. In nerve-intact rats, intrathecal NGF (1 mg/ml, 14 days) but not GDNF (1 mg/ml, 14 days) induced extensive sprouting of tyrosine hydroxylase immunoreactive (TH-IR) fibres and formation of pericellular TH-IR baskets within lumbar DRGs. TH-IR baskets were distributed equally to trkA-expressing and trkA-negative neuronal profiles.