“
“Numerous studies in animals and humans have related central aspects of Stem Cell Compound Library chemical structure somatosensory

working memory function to neural activity in the inferior frontal gyrus (IFG). However, as previous studies have almost exclusively used correlational analyses, the question whether sustained neural activity in the IFG is causally involved in successful maintenance of somatosensory information remains unanswered. We used an online repetitive transcranial magnetic stimulation (rTMS) protocol to disrupt neuronal activity in the IFG while participants were maintaining tactile information throughout the delay for later comparison against a probe stimulus. rTMS impaired participants’ performance in the working memory task, but

not in a physically matched perceptual control task. Targeting the IFG in either hemisphere led to comparable working memory impairment. Our results show that the neural activity in the IFG plays a causal role in successful maintenance of somatosensory information. “
“A goal-directed navigation model is proposed based on forward linear look-ahead probe of trajectories in a network of head direction cells, grid cells, place cells and prefrontal cortex (PFC) cells. The model allows Alectinib research buy selection the of new goal-directed trajectories. In a novel environment, the virtual rat incrementally creates a map composed of place cells and PFC cells by random exploration. After exploration, the rat retrieves memory of the goal location, picks its next movement direction by forward linear look-ahead probe of trajectories in several candidate directions while stationary in one location, and finds the one activating PFC cells with the highest reward signal. Each probe direction involves activation of a static pattern of head direction cells to drive an interference

model of grid cells to update their phases in a specific direction. The updating of grid cell spiking drives place cells along the probed look-ahead trajectory similar to the forward replay during waking seen in place cell recordings. Directions are probed until the look-ahead trajectory activates the reward signal and the corresponding direction is used to guide goal-finding behavior. We report simulation results in several mazes with and without barriers. Navigation with barriers requires a PFC map topology based on the temporal vicinity of visited place cells and a reward signal diffusion process. The interaction of the forward linear look-ahead trajectory probes with the reward diffusion allows discovery of never-before experienced shortcuts towards a goal location.