2024-03-29T04:44:47Z
https://repository.dl.itc.u-tokyo.ac.jp/oai
oai:repository.dl.itc.u-tokyo.ac.jp:00002316
2022-12-19T03:43:58Z
125:348:349
9:233:280
前交連を介した左右嗅皮質間の相互作用
Interactions between right and left olfactory cortices via the anterior commissure
菊田, 周
6516
University of Tokyo (東京大学)
博士(医学)
Visual and auditory systems use two sensory organs to monitor the external sensory signals. In olfactory systems, odors are inhaled through the nostrils into two segregated nasal passages and processed by two, right and left olfactory pathways. Anterior olfactory nucleus (AON) of the adult rat olfactory cortex receives excitatory axonal inputs from ipsi-lateral olfactory bulb and also receives inputs from contra-lateral olfactory cortex via the anterior commissure (AC), suggesting that it receives converging inputs from ipsi-lateral and contra-lateral olfactory epithelia. To study the functional interactions between right and left olfactory pathways, I recorded extracellular single unit activity of AON neurons and examined their responses to ipsi-nasal and contra-nasal stimulation with 10 odorant categories. I found 1) that about 60 % neurons in the AON received converging excitatory inputs from both olfactory epithelia, 2) that these binasal neurons were preferentially located in the deep part of the layerⅡ in the AON, and 3) that binasal neurons in the AON respond to ipsi-nasal and contra-nasal inputs with nearly-equivalent odorant category selectivity. Furthermore, deprivation of ipsi-nasal inputs by unilateral nostril obstruction greatly enhanced the response to contra-lateral odor stimulation, in a reversible manner, in about 33% of AON neurons within only several minutes. In 27% of AON neurons that showed spike responses induced by the inspiration of room air, ipsi-lateral nasal obstruction initially suppressed respiration phase-locked spike discharges and, several minutes later, induced respiration phase-locked discharges with longer delays between inspiration and response. Recordings from AON neurons in rats with AC transection indicated that the resumed respiration phase-locked discharges with longer delays were mediated by the contra-lateral pathway via the AC. The ipsi-nasal occlusion-induced switching of nasal inputs to individual AON neurons shows that a subset of AON neurons in the adult rat has neuronal mechanisms for rapid nostril dominance plasticity, which may enable both right and left olfactory cortices to preserve their responsiveness to the external odor world, despite reciprocal changes in nasal airflow
thesis
2009-03-23
2009-03-23
application/pdf
甲第24894号
https://repository.dl.itc.u-tokyo.ac.jp/record/2316/files/41_kikuta.pdf
eng