Synaptic Plasticity and Synchronization of Thalamocortical Theta Band Modulated by Perceptual Visceral Pain Learning

Repetitive distension of the colon and rectum (rCRD) was used as a sensitization paradigm. We identified enhancement of synaptic efficacy in the medial thalamus (MT)-anterior cingulate cortex (ACC) synapses after induction of visceral hypersensitivity in the rCRD rats. Theta burst stimulation (TBS) reliably induced long-term potentiation (LTP) in the MT-ACC pathway in control rats, however, the expression of LTP was impaired in the rCRD rats.

High-density multichannel arrays of electrodes were implanted in the MT and ACC of freely moving rats before and after repeated CRD treatment. Local field potentials (LFPs) were amplified (×20,000), band-pass filtered (0.05-200 Hz, 4-pole Bessel), and sampled at 1k Hz. Local field potentials (LFPs) were recorded before rCRD treatment, 15 min and 6 hr after rCRD cessation. We demonstrated that visceral hypersensitivity associated with enhanced MT-ACC synaptic efficacy, the increases in the power of theta oscillation, and synchronization of thalamocortical theta band LFP can contribute to the enhanced ACC neuronal response to noxious visceral stimulation and behavioural pain.

Neuronal activities in the ACC and MT in pre-rCRD, 15 min and 6 h post –rCRD during spontaneous and CRD.

Publication and Conference Presentations

1. T. Chung, J. Q. Wang, J. Wang, B. Cao, Y. Li, and S. W. Pang, “Electrode modifications to lower electrode impedance and improve neural signal recording sensitivity”, J. Neural Eng. 12:056018 (2015).
2. L. Mu, J. Wang, B. Cao, B. Jelfs, R.H.M. Chan, X. Xu, M. Hasan, X. Zhang, and Y. Li, "Impairment of cognitive function by chemotherapy: association with the disruption of phase-locking and synchronization in anterior cingulate cortex", Molecular Brain 8, 32 (2015).
3. J. Wang, B. Cao, T.R. Yu, B. Jelfs, J. Yan, R.H.M. Chan, and Y. Li, "Theta-frequency phase-locking of single anterior cingulate cortex neurons and synchronization with the medial thalamus are modulated by visceral noxious stimulation in rats", Neuroscience 298, 200-210 (2015).
4. X. Xu, B. Cao, J. Wang, T. Yu, and Y. Li, "Decision-making Deficits Associated with Disrupted Synchronization between Basolateral Amygdala and Anterior Cingulate Cortex in Rats after Tooth Loss", Progress in Neuro-Psychopharmacology & Biological Psychiatry 60, 26-35 (2015).
5. J. Wang, X. Zhang, B. Cao, J. Liu, Y. Li, “Facilitation of synaptic transmission in the anterior cingulate cortex in the viscerally hypersensitive rats”, Cerebral Cortex, October 2013.
6. Y. Li, “Facilitation of Synaptic Transmission in the Anterior Cingulate Cortex in Viscerally Hypersensitive Rats”, 2013 International Forum on Anesthesiology and Pain Conference Montreal, Canada, October 19-20, 2013.
7. Y. Li, “Advancements in Visceral Pain Research”, Pain research Symposium Shanghai institute of digestive disease, October 11-16, 2013.
8. Y. Li, “Vagal Nerve Stimulation Suppresses Visceral Pain”, Gin Hai Medical University China, July 2013.