LOCAL MODULATION OF CORTICAL SLOW OSCILLATION RHYTHM BY TEMPERATURE

The mammalian neocortex exhibits recurrent, rhythmic, and highly synchronous activity during physiological slow-wave sleep and under anesthesia. This activity is characterized by the slow oscillation rhythm (SO), which alternates between periods of high neuronal activity (Up state) and silence (Down state) at approximately 1Hz. Conversely, temperature is a fundamental regulator of homeostasis influencing different aspects of brain physiology, such as neuronal excitability, synaptic transmission, and network dynamics. Previous work demonstrated that raising global temperature from 34°C to 40°C enhances cortical synchronization [1]. In the current study, we aimed to determine whether local temperature variations affect cortical SO dynamics. We studied the impact of both local and global temperature increases in cerebral cortex slices in vitro, while recording with a 32-multielectrode surface array. To control and monitor temperature, we combined the recordings with an ad hoc designed probe that can locally increase the temperature in four locations of the slice and a high-resolution thermographic camera to monitor local changes in temperature. This set up allowed us to monitor and modulate temperature on a spatiotemporal scale. Under these experimental conditions, local temperature elevations rapidly enhanced SO synchronization and frequency. Moreover, this effect progressively diminished with increasing distance from the heated region. Overall, our findings reveal a tight coupling between cortical slow-oscillation dynamics and local temperature variations, highlighting temperature as a spatially specific mechanism for shaping cortical network dynamics and synchronization. [1] Reig et al (2010). Journal of Neurophysiology, 103(3), 1253-1261.