Università Campus Bio-Medico

About: Università Campus Bio-Medico is a education organization based out in Rome, Italy. It is known for research contribution in the topics: Population & Medicine. The organization has 2829 authors who have published 8519 publications receiving 193689 citations. The organization is also known as: Universita Campus Bio-Medico & Campus Bio-Medico University.

Driving Human Motor Cortical Oscillations Leads to Behaviorally Relevant Changes in Local GABAA Inhibition: A tACS-TMS Study.

Abstract: Beta and gamma oscillations are the dominant oscillatory activity in the human motor cortex (M1). However, their physiological basis and precise functional significance remain poorly understood. Here, we employed Transcranial Magnetic Stimulation (TMS) to examine the physiological basis and behavioural relevance of driving beta and gamma oscillatory activity in the human M1 using transcranial alternating current stimulation (tACS). tACS was applied using a sham-controlled cross-over design at individualised intensity for 20 min, and TMS was performed at rest (before, during and after tACS) and during movement preparation (before and after tACS). We demonstrated that driving gamma frequency oscillations using tACS led to a significant, duration-dependent decrease in local resting-state GABA A inhibition, as quantified by short interval intracortical inhibition (SICI). The magnitude of this effect was positively correlated with the magnitude of GABA A decrease during movement preparation, when gamma activity in motor circuitry is known to increase. In addition, gamma tACS-induced change in GABA A inhibition was closely related to performance in a motor learning task, such that subjects who demonstrated a greater increase in GABA A inhibition also showed faster short-term learning. The findings presented here contribute to our understanding of the neurophysiological basis of motor rhythms, and suggest that tACS may have similar physiological effects to endogenously driven local oscillatory activity. Moreover, the ability to modulate local interneuronal circuits by tACS in a behaviourally relevant manner provides a basis for tACS as a putative therapeutic intervention. SIGNIFICANCE STATEMENT Gamma oscillations have a vital role in motor control. Using a combined tACS-TMS approach, we demonstrate that driving gamma-frequency oscillations modulates GABA A inhibition in the human motor cortex. Moreover, there is a clear relationship between the change in magnitude of GABA A inhibition induced by tACS and the magnitude of GABA A inhibition observed during task-related synchronisation of oscillations in inhibitory interneuronal circuits, supporting the hypothesis that tACS engages endogenous oscillatory circuits. We also show that an individual9s physiological response to tACS is closely related to their ability to learn a motor task. These findings contribute to our understanding of the neurophysiological basis of motor rhythms and their behavioural relevance, and offer the possibility of developing tACS as a potential therapeutic tool.

Bisphosphonates and osteomyelitis of the jaw: a pathogenic puzzle.

Abstract: The maxillary and mandibular bones undergo high-turnover remodeling to maintain mechanical competence. Common dental or periodontal diseases can increase local bone turnover. Bisphosphonates (BPs) accumulate almost exclusively in skeletal sites that have active bone remodeling. The maxillary and mandibular bones are preferential sites for accumulation of BPs, which become buried under new layers of bone and remain biologically inactive for a long time. Surgical odontostomatological procedures create open bony wounds that heal quickly and without infection, as a result of activation of osteoclasts and subsequently osteoblasts. Once BPs are removed from the bone via activation of osteoclasts after a tooth extraction or a periodontal procedure, they induce osteoclast apoptosis. This inhibition of osteoclast bone resorption impairs bone wound healing because of decreased production of cytokines derived from the bone matrix, and the bone is exposed to the risk of osteomyelitis and necrosis. The pathogenic relationship between BPs and osteonecrosis of the jaw is unclear, but there is evidence to indicate an association between high-dose BP treatment and exposure to dental infections or oral surgical procedures. A better knowledge of the interactions between BPs and jaw and maxillary bone biology will improve clinical and therapeutic approaches.