Chemosensitivity of medullary neurons in explant tissue cultures.
Chemosensitivity of medullary neurons in explant tissue cultures.
复制标题
外植体组织培养中髓质神经元的化学敏感性。
DOI：
10.1016/0306-4522(91)90282-s
复制
发表时间：
1991
期刊：
影响因子：
3.3
通讯作者：
Edelman,NH
中科院分区：
文献类型：
--
作者：
Neubauer,JA;Gonsalves,SF;Chou,W;Geller,HM;Edelman,NH
To determine whether cultured medulla contains chemosensitive neurons which are excited by CO2and fixed acid and whether this function is specific to the ventral medulla, tissue expiants of ventral and dorsal medulla were prepared from neonatal rats and incubated for two to three weeks. Cultures were superfused with artificial cerebrospinal fluid, maintained at 37°C, and pH of the superfusate was varied either with PCO2(14–71 Torr) at constant HCO3−(22 mM) or HCO3−(10–30 mM) at constant PCO2(35 Torr). Spontaneous action potentials were recorded extracellularly in 51 ventral and 23 dorsal medullary neurons. Ventral medullary neurons exhibited a steady baseline firing frequency of4 ± 0.8Hz. In contrast, dorsal medullary neurons exhibited two different patterns of spontaneous activity: 11 fired continuously (7.2 ± 1.4Hz) while 12 fired with a bursting pattern. Burst duration was0.80 ± 0.14min and cycle time was1.74 ± 0.43min. Decreasing pH with CO2caused an increase in the activity of 10 of 27 ventral medullary neurons and two of six dorsal medullary neurons with a mean response of 7.5 Hz/pH unit. Varying pH by changing HCO3−had no effect on firing frequency.These results demonstrate that: (i) chemosensitive neurons are present in both ventral and dorsal medullary expiant cultures; (ii) these cells only respond to changes in pH induced with CO2; and (iii) about half of the dorsal medullary neurons fire spontaneously with a regular bursting pattern of activity.
