Bushnik T, Bielajew C, Konkle A T
TBI/SCI Grants Office, 95128, San Jose, CA, USA.
Brain Res. 2000 Oct 27;881(2):103-11. doi: 10.1016/s0006-8993(00)02564-6.
Given the putative role of the lateral preoptic area as a primary contributor of the cell bodies of origin of the descending pathway linking a subset of lateral hypothalamic and ventral tegmental area reward neurons, the distribution of self-stimulation sites in this structure was mapped in 22 animals using moveable electrodes and threshold procedures. Ninety-seven electrode sites were evaluated with placements ranging from just rostral to the midline convergence of the anterior commissure back to the transition zone between the lateral preoptic and lateral hypothalamic areas; of these, roughly 2/3 supported self-stimulation which was widely observed throughout the lateral preoptic area and medial forebrain bundle. In general, self-stimulation thresholds obtained from lateral sites were most stable, and progressively so approaching more caudal regions. Examination of the slopes of the period/current trade-off functions revealed a tendency for higher values in lateral and caudal sites; in contrast, dorsoventral excursions did not influence these estimates. Taken together, these data provide support for the notion that the substrate for brain-stimulation reward in the lateral preoptic area has a relatively homogeneous distribution that is more diffusely organized than that found in reward sites activated further caudally in the medial forebrain bundle.
鉴于外侧视前区被认为是连接下丘脑外侧和腹侧被盖区一部分奖赏神经元的下行通路起源细胞体的主要贡献者，使用可移动电极和阈值程序在22只动物中绘制了该结构中自我刺激位点的分布图。对97个电极位点进行了评估，其位置范围从紧靠前连合中线汇聚的喙侧到外侧视前区和下丘脑外侧区之间的过渡区；其中，大约2/3的位点支持自我刺激，在整个外侧视前区和内侧前脑束中广泛观察到。一般来说，从外侧位点获得的自我刺激阈值最稳定，并且越靠近尾侧区域越稳定。对周期/电流权衡函数斜率的检查显示，外侧和尾侧位点的值有升高的趋势；相比之下，背腹偏移不影响这些估计值。综上所述，这些数据支持了这样一种观点，即外侧视前区中脑刺激奖赏的底物具有相对均匀的分布，其组织比在内侧前脑束中更靠尾侧激活的奖赏位点更分散。
