Rangel S, Leon M
Department of Psychobiology, University of California, Irvine 92717, USA.
Brain Res Dev Brain Res. 1995 Apr 18;85(2):187-91. doi: 10.1016/0165-3806(94)00211-h.
In vivo microdialysis sampling of the olfactory bulbs of awake rats on PND 3 revealed that olfactory stimulation alone does not alter extracellular norepinephrine (NE) levels. Tactile stimulation that is designed to mimic maternal interactions with the young does increase bulb NE and the combined odor and tactile stimulation further increases NE levels. These data are consistent with a critical role for NE in the development of early olfactory preferences in infant rats, induced by odor/tactile stimulation pairings. PND 10 odor/tactile stimulation does not evoke an increase in NE, data consistent with the finding that odor preference training of this kind is ineffective after about the first week of life. Oral infusion of milk on PND 3 also increases bulb NE, a finding consistent with the role of milk as a reinforcing stimulus for the development of early olfactory preferences. Finally, infusion of potassium into the bulb on PND 3 produces a rapid increase in NE, indicating a local neuronal origin of the NE in response to stimulation.
在出生后第3天对清醒大鼠嗅球进行的体内微透析采样显示，单纯的嗅觉刺激不会改变细胞外去甲肾上腺素（NE）水平。旨在模拟母体与幼崽互动的触觉刺激确实会增加嗅球NE水平，而气味和触觉刺激相结合会进一步提高NE水平。这些数据与NE在由气味/触觉刺激配对诱导的幼鼠早期嗅觉偏好发展中起关键作用一致。出生后第10天的气味/触觉刺激不会引起NE增加，这一数据与如下发现一致：大约在出生后第一周后，这种气味偏好训练无效。出生后第3天经口注入牛奶也会增加嗅球NE，这一发现与牛奶作为早期嗅觉偏好发展的强化刺激物的作用一致。最后，出生后第3天向嗅球注入钾会使NE迅速增加，表明NE在受到刺激时源于局部神经元。
