Pascoe J P, Kapp B S
Neuroscience. 1987 May;21(2):471-85. doi: 10.1016/0306-4522(87)90136-9.
Recent evidence suggests that the amygdaloid central nucleus may contribute importantly to autonomic regulation during emotional states, possibly via both direct and indirect central nucleus efferent projections to autonomic regulatory nuclei in the lower brainstem. Additional findings suggest that the insular cortex may participate in autonomic regulatory processes, possibly by exerting an influence upon central nucleus neuronal activity via its direct projections to the central nucleus. The present experiment was conducted to determine the effects of insular cortex stimulation upon extracellularly recorded central nucleus neuronal activity in conscious, drug-free, rabbits. Satisfactory recordings were obtained from 146 central nucleus neurons. These were classified as belonging to one of six general categories on the basis of rates and patterns of ongoing discharge, responses to an auditory stimulus, and location within the nucleus. Determinations were then made as to whether each neuron could be activated antidromically from a ventrolateral mesencephalic region through which descending central nucleus projections to the lower brainstem course, and hence, whether the neuron might contribute to these projections. The activity of each neuron was then assessed during single-pulse stimulation of the region of the insular cortex demonstrated previously to project to the central nucleus. Such stimulation produced no response, an initial increase, or an initial decrease in the activity of 33%, 53% and 14% of the 146 neurons, respectively. The predominant response consisted of a single spike with a short but variable onset latency, suggesting orthodromic activation via one or a few synapses. Included among the neurons that responded to stimulation of the insular cortex in this manner were seven of 22 central nucleus neurons identified as projecting to the lower brainstem. Responses consisting of initially decreased activity most often occurred in neurons that discharged infrequently and were sensory-responsive. The results of this experiment thus provide more detailed information than was available previously regarding the pervasive influence of the insular cortex upon central nucleus neuronal activity, and provide further support for the notion that the insular cortex may participate in autonomic regulatory processes by way of its direct projections to the central nucleus.
最近的证据表明，杏仁核中央核可能在情绪状态下对自主神经调节起重要作用，可能是通过中央核向脑干下部自主神经调节核的直接和间接传出投射。其他研究结果表明，岛叶皮质可能参与自主神经调节过程，可能是通过其向中央核的直接投射对中央核神经元活动产生影响。进行本实验是为了确定刺激岛叶皮质对清醒、未用药家兔细胞外记录的中央核神经元活动的影响。从146个中央核神经元获得了满意的记录。根据持续放电的速率和模式、对听觉刺激的反应以及在核内的位置，将这些神经元分为六个一般类别之一。然后确定每个神经元是否可以通过中脑腹外侧区域进行逆向激活，中央核向下投射到脑干下部的纤维束通过该区域，因此，该神经元是否可能对这些投射有贡献。然后在单脉冲刺激先前已证明投射到中央核的岛叶皮质区域期间评估每个神经元的活动。这种刺激分别使146个神经元中的33%、53%和14%的神经元活动无反应、最初增加或最初减少。主要反应包括一个单峰，起始潜伏期短但可变，表明通过一个或几个突触进行顺向激活。以这种方式对岛叶皮质刺激有反应的神经元中，有22个被确定为投射到脑干下部的中央核神经元中的7个。最初活动减少的反应最常发生在放电不频繁且对感觉有反应的神经元中。因此，本实验的结果比以前提供了关于岛叶皮质对中央核神经元活动的广泛影响的更详细信息，并为岛叶皮质可能通过其向中央核的直接投射参与自主神经调节过程的观点提供了进一步支持。
