Pandhari S R, Desiraju T
Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Bangalore.
Indian J Physiol Pharmacol. 1990 Oct;34(4):235-51.
It was aimed to study the effects of lesions of a self-stimulation (SS) area of one region of brain on the SS of another region, and on feeding behaviour in adult Wistar rats (males). The two regions proposed for study were the lateral hypothalamus (LH) and the substantia nigra-ventral tegmental area (SN-VTA). The objective was to elucidate whether each region had its own neural organization for SS behaviour or not, and whether the neural substrates of SS behaviour and feeding behaviour were one, or separate. Four bipolar electrodes were implanted bilaterally in LH and SN-VTA in each rat, and their SS pedal press rates for rewarding electrical stimulations were characterised. The rats were also trained in operant conditioning paradigm for receiving reward of food grains in FR-30 schedule. Their free-field food intake in home cages was measured. Later, electrolytic lesions of the four electrode sites were made one after another at 2-day intervals through the same biopolar electrodes. After each lesioning, the SS of the same and of the other electrode sites, and the operant performance of FR-30 food reward schedule, and daily free-field food intake (in home cage) were determined. Lesions of the LH SS site always disrupted SS-of contralateral LH but not of SN-VTA SS. Lesions of SN-VTA had not modified contralateral SN-VTA SS. A study of effects of ipsilateral lesions of LH SS site on SN-VTA SS, or of lesions of SN-VTA SS site on LH SS, revealed a range of changes, as were also effects on the FR-30 operant performance and daily food intake. Medium size lesions of SS area made in one region affected the SS of that area but not usually the SS of the other region. Large lesions of one region affected the SS of the other regions also. With large lesions, feeding behaviour also was affected, firstly of the operant type and secondly the free-field type.
本研究旨在探讨损毁成年雄性Wistar大鼠脑内一个区域的自我刺激（SS）区对另一区域SS以及进食行为的影响。拟研究的两个区域为外侧下丘脑（LH）和黑质-腹侧被盖区（SN-VTA）。目的是阐明每个区域是否具有自身独立的SS行为神经组织，以及SS行为和进食行为的神经基础是同一的还是分开的。在每只大鼠的LH和SN-VTA双侧植入四对双极电极，并对其因电刺激奖赏而产生的SS踏板按压频率进行表征。大鼠还接受操作性条件反射范式训练，按照FR-30程序获取谷物奖励。测量它们在饲养笼中的自由进食量。之后，通过同一双极电极每隔2天依次对四个电极位点进行电解损伤。每次损伤后，测定同一电极位点和另一电极位点的SS、FR-30食物奖励程序的操作性表现以及每日自由进食量（在饲养笼中）。LH的SS位点损伤总是破坏对侧LH的SS，但不影响SN-VTA的SS。SN-VTA的损伤未改变对侧SN-VTA的SS。对LH的SS位点同侧损伤对SN-VTA的SS的影响，或SN-VTA的SS位点损伤对LH的SS的影响的研究，揭示了一系列变化，这些变化对FR-30操作性表现和每日食物摄入量也有影响。一个区域的SS区中等大小损伤影响该区域的SS，但通常不影响另一区域的SS。一个区域的大损伤也会影响另一区域的SS。大损伤时，进食行为也会受到影响，首先是操作性进食行为，其次是自由进食行为。
