title: From Nose to Brain: Un-Sensed Electrical Currents Applied in the Nose Alter Activity in Deep Brain Structures.
abstract: Rules linking patterns of olfactory receptor neuron activation in the nose to activity patterns in the brain and ensuing odor perception remain poorly understood. Artificially stimulating olfactory neurons with electrical currents and measuring ensuing perception may uncover these rules. We therefore inserted an electrode into the nose of 50 human volunteers and applied various currents for about an hour in each case. This induced assorted non-olfactory sensations but never once the perception of odor. To validate contact with the olfactory path, we used functional magnetic resonance imaging to measure resting-state brain activity in 18 subjects before and after un-sensed stimulation. We observed stimulation-induced neural decorrelation specifically in primary olfactory cortex, implying contact with the olfactory path. These results suggest that indiscriminate olfactory activation does not equate with odor perception. Moreover, this effort serendipitously uncovered a novel path for minimally invasive brain stimulation through the nose.
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Tali
authors: T
authors: Weiss
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.|Department of Otolaryngology-Head and Neck Surgery, Edith Wolfson Medical Center, Holon 58100, Israel.
authors: Sagit
authors: S
authors: Shushan
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Aharon
authors: A
authors: Ravia
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Avital
authors: A
authors: Hahamy
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Lavi
authors: L
authors: Secundo
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Aharon
authors: A
authors: Weissbrod
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Aya
authors: A
authors: Ben-Yakov
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Yael
authors: Y
authors: Holtzman
authors: Department of Otolaryngology-Head and Neck Surgery, Edith Wolfson Medical Center, Holon 58100, Israel.
authors: Smadar
authors: S
authors: Cohen-Atsmoni
authors: Department of Otolaryngology-Head and Neck Surgery, Edith Wolfson Medical Center, Holon 58100, Israel.
authors: Yehudah
authors: Y
authors: Roth
authors: Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors: Noam
authors: N
authors: Sobel
keywords: brain stimulation; default-mode network; olfactory cortex; olfactory epithelium; olfactory perception; resting-state activity