Di Lorenzo P M, Monroe S
Department of Psychology, State University of New York, Binghamton 13902-6000.
Brain Res Bull. 1992 Dec;29(6):925-30. doi: 10.1016/0361-9230(92)90167-v.
Taste responses in units in the parabrachial nucleus of the pons (PbN) that receive direct projections from the gustatory neocortex (GN) were examined in the rat. Electrical stimulation was applied to the GN with bipolar stimulating electrodes. Time-locked responses to GN stimulation were observed in 19 of 62 (31%) taste-responsive units identified in the PbN. Of these, 17 units produced excitatory responses following GN stimulation and 2 units showed evidence of inhibition. No evidence of antidromic activation of PbN units was apparent. These results are consistent with descriptions of the anatomical projections from the GN to the PbN and demonstrate that some portion of taste-responsive neural elements within the PbN receive direct cortical input. PbN units that followed GN stimulation could not be distinguished from those that did not follow either by their spontaneous rates or their response profiles. These results suggest that axons from the GN do not select targets within the PbN based on the particular response properties.
在大鼠中，对脑桥臂旁核（PbN）中接受来自味觉新皮层（GN）直接投射的神经元的味觉反应进行了研究。用双极刺激电极对GN施加电刺激。在PbN中鉴定出的62个味觉反应神经元中，有19个（31%）观察到了对GN刺激的锁时反应。其中，17个神经元在GN刺激后产生兴奋反应，2个神经元表现出抑制迹象。未发现PbN神经元有逆向激活的明显证据。这些结果与从GN到PbN的解剖学投射描述一致，并表明PbN内部分味觉反应神经元接受直接的皮层输入。对GN刺激有反应的PbN神经元，无论是自发放电率还是反应特征，都无法与无反应的神经元区分开来。这些结果表明，来自GN的轴突不会根据特定的反应特性在PbN内选择靶点。
